Tip on how to pronounce the name of this font: You first have to know the pronunciation of Polish words: The most important part is don't use a Russian accent.
 

Many Polish learners put on a faux "Polish accent" when speaking Polish. The problem is, the most common tutorial for a Polish accent there is on YouTube sounds too much like a Russian Accent. I'm Polish and this accent sounds Russian to me. They use drag out vowels, like russian, for example "ije" and "uo". Polish, has dry vowels, like "e" (not ije) and "o" (not uo), like Spanish or Italian. Also, their "fake Polish" Y vowel is too "front" in the mouth, like in a "Russian" accent.
I'm Polish and I'm sad when people say "use russian accent, make your sounds in the front of the mouth and it's Polish". It sounds wrong. Here's a better tip from me, still not 100% perfect but better: "For a Polish accent, use Italian accent sounds, but with English intonation patterns. Also, don't use Italian closed e and o, only use the open ones. Also, make your ch(roughly h in hat), sz(roughly sh in shop), and cz(roughly tch in catch) sound harsher, like Greek χ for ch (has to be velar, saying it in a uvular way will sound like a Dutch accent, not Polish), russian Ш for sz and Chinese 吃 for cz. Add the Polish Y sound, try to imitate a Polish speakers. "Pushing" your tongue too much into the front so that it sounds like "ii" will make it sound more "Russian", which is wrong. Nasal vowels are like Italian open E and O, but with a nasal W sound after them. Ń and Ni is a Spanish Ñ sound, and Ł is W sound as in "water" or "why", as opposed to a Л sound, which would sound too Russian". And if you DID use a Russian accent for Polish some time in your life, don't worry, it's alright, many people make that mistake. Even the famous children's TV show made this mistake, in their episode where the scammers switch Martha's soup for Polish soup and she speaks Polish. Martha's sentences sound like a "Russian accent", for example the sentence "Ktoś podmienił moją zupę", said by Martha, sounds like (respelled phonetically in the REAL Polish letters) "Ktuoś płodmijenil młojo żupa", sounds too "Russian".

Specific Polish letter sounds:

Vowels:
A a: sounds like European Spanish or Italian "a". Your tongue should be in a Goldilocks zone, near the center of the mouth. If it's too front, it will sound like a British accent or an American Spanish accent, if it's too backed, it will sound Russian. Adding a throatiness, like people often do to imitate a Slavic sound, is a bad thing, it will make it sound Russian, or even Southern US like Texas.
E e: sounds exactly like English "e" in "bed", or Italian "è" as in caffè. Don't say "ije" or "i-ye", it will sound Russian.
I i: sounds like a European "i", very similar to American "y" as in Happy. Avoid making it longer like in British ee as in bee, it would sound too Russian.
O o: sounds like Italian "ò" as in "andrò". In British English, this sound exists in "hot" or "lot", but it's hard to get right for Americans. The tongue should be in the back of the mouth, but don't make it too back, it will sound Arabic or American. It should be a monophthong, or single pure vowel sound. If you make it a closing diphthong like "ou", it would sound too English. If you make it an opening diphthong like "uo", it would sound too Russian. Ideally, it should be a pure vowel, the tongue should be in the back part of the mouth but not too far in the throat, like in British English or Italian.
U u: Sounds like European "u", like in Spanish, Italian, or Russian. Don't make it too long, it will sound too much like Old English.
Ó ó: Same as the "u". U and Ó are pronounced the same.
Y y: This is difficult to get right. The tongue should be relaxed, and the tip of the tongue should be right behind the bottom teeth. The lips should be in a relaxed position, almost like you're saying "uhh". Avoid "pushing" your tongue too far into the front, it would make it sound "Russian". If your tongue is too far back, it would make it sound more "South Slavic" or even "Kazakh".
Ą ą: Like Italian "ò", but with the nasal sound added after it
Ę ę: Like Italian "è", but with the nasal sound added after it
Nasal vowel sound: Like english "w" as in "water" or "why", but nasalized. Add it after Italian vowels (ò, è) to make it sound Polish (ą, ę). In fast speech it can be replaced with an N like sound in the middle of words, or dropped at the end of words. Avoid over-pronouncing it like "e-wu" for ę, it would sound like you're a clown or an alien who can't really speak.

Two-letter consonants with single sounds (called "digraphs" in linguistics):
Ch: sounds like Greek χ or Russian х, should be velar not uvular. To get the right sound, try to prolong a K sound as in "Kah", until you get a harsh sound, but not too harsh. If you make it too harsh(uvular, pharyngeal), it would sound like a different language accent, such as German, Spanish, Dutch, Kazakh, or even Arabic.
Cz: sounds like a hard "Chh". Ideally, it should be retroflex, like Russian Ш or Chinese 吃. Try to position your tongue as if saying Russian Ш, but say Ch instead of Sh. In some non-Slavic language using the Cyrillic script, the letter Ҽ may be used for this sound.
Dz: sounds like the European "Italian-style" double "z" sound, as in the word "l'orizzonte" in Italian. In English, saying "adze" or "Lindsay" can make a similar sounds, but it might not be the exact same in some dialects of English.
Dż: Put your tongue in the Ш position and say the J/G sound, as in "George".
Rz: Sounds like Ж in Russian, but after "P T K CH" it is softened to a Russian Ш.
Sz: Sounds like Ш in Russian.

Alveolo-Palatal sounds (also called "soft sounds" in the context of the Polish language):
Tongue position: The "soft" tongue position is complicated for foreigners. The tip of the tongue is right behind the alveolar ridge (compare "sh" in shoe), and the body of the tongue should be stuck flat on the hard palate (compare "y" in yellow). As an exercise to get it right, try to quickly alternate like "sh-y-sh-y-sh-y" and slowly transition "shhhh-yyy", and try to find a position in the middle of Sh and Y sound. You can easily detect these in Polish writing, these are indicated by either consonant + letter i or consonant with a "´" accent  on the top.
Ś ś si: sounds like Russian Щ. It's like sh but with the soft tongue. In Japanese, this sound is written as し, and in Chinese, it's written as 希.
Ź ź zi: almost like S in measure, but with the soft tongue. This sound exists in some dialects in Russian (but only some dialects), in the word позже. In Japanese, this sound is written as じ, but only the dialects that differentiate じ and ぢ say it in a clear Polish-like way.
Ć ć ci: like Russian Ч. It's like ch but with the soft tongue. In Japanese, this sound is written as ち, and in Chinese, it's written as 七.
Dź dź dzi: almost like G in George, but with the soft tongue. In Japanese, this sound is written as ぢ, and in Chinese, it's written as 鸡.
Ń ń ni: Sounds like spanish Ñ.
other sounds written CiV (consonant, then "i", followed by another vowel), are pronounced as palatalized versions of other sounds. The "i" here, represents a short y-like sound. In Russian, the letters are written as iotated vowels (bia = бя, bie = бе), in Japanese, these are written as small letters (bia = びゃ), and in Chinese, they are written as "i" in pinyin (bie = 𤉤, Pinyin: biē)

Other sounds:
J j: Sounds like Y, as in "yellow"
C c: Sounds like Russian Ц, or Italian Z (as in Zio)
H h: sounds the same as ch in most dialects, but other dialects have a distinctive dry sound, like the Greek γ
R r: this has 2 variants. In slow speech, where you enunciate each word, it makes a rolled r sound, like in Spanish "perro".  In fast speech, it sounds like a tapped r, like American tt in butter. Avoid rolling it with your throat, people will think you have a speech impediment. Ideally, the tip of the tongue should touch the roof of the mouth right behind the top teeth.
L l: sounds like a light L, like British English "lamp", Italian "luce", French "lui" or Spanish "leche". Avoid using a dark L sound, it will sound like a "Russian" or "Ukrainian" accent.
Ł ł: sounds like W as in "water" or "why". Avoid pronouncing it like Л, it will sound like a Russian accent (Disclaimer: in old movies, people DO pronounce it like Л, but it's just an old pronunciation, no one says it like that now)
W w: Sounds like V as in "van" or "vase", but before and after "T K C Ć CH SZ CZ S Ś" it softens into an "F" sound as in "fan" or "face".
Ż ż: sounds like Russian Ж.

Stress: Normally on second to last syllable. There are some exceptions but these aren't very common words.

And now, you can say stuff like "Grzegorz Brzęczyszczykiewicz" pronounced "Gжègòш BжènҼyшҼykʸèveeҼ"

This is the font. The lowercase forms of g with diacritics in Latin Extended-A will be made after I make IPA extensions because I first need to change the main form of the g to double storey so that the script g in IPA extensions will be distinct in this font.

New Grzegorz Brzęczyszczykiewicz update:

more letters

I know