Salam. Esm-e-man Ashley-e(Or you can say: Man Ashley hasstam. this one is formal). Man amreekayee hastam.
I am 21 years old (Man 21 Saal daa-ram, Or Man 21 Saa-le hass-tam) and I live in Boston, MA (Va dar Boston, MA Zen-de-gee Mi-konam).
About your last sentence, I must say we don't say " I go to school at a university ...".
We say "I go to a school in Boston as well." ( Man be yek/ Ye Mad-re-se dar Boston Mi-Ravam/ Mir-Ram) Or " I go to a university in Boston as well. ( Man be Yek/ Ye Daa-nesh-Gaah dar Boston Mi-Ravam/ Mi-Ram)
Notice that "Ye" and "Mi-Ram" both are informal. but "Yek" and "Mi-Ravam" are formal.
FYI: School= Mad-Re-Se مدرسه
High School= Da-Bi-Res-Taan دبیرستان
University= Daa-Nesh-Gaah دانشگاه
Pre-University= Peesh Daa-Nesh-Gaahee پیش دانشگاهی
I hope you soon becom fluent in Farsi.
Good luck = Mo-va-f-fa-gh baa=shee
Haasan