> I'm learning english, i wanna do it more interesting with language mates.

In English, names of languages are one type of proper noun (and, accordingly, they are capitalized). You would want the word and after the comma, since there is a grammatically complete clause on either side (on both sides) of the comma. Finally, the verb you want for the expression in the second clause is make: I'm learning English, and I want to make it more interesting with language mates.

As far as the word mates goes, it's common in Australian and British English, less so in American. Mates tends to mean something more like pals or friends, but partners is the word we'd be more like to use here: I'd go for [name of language] conversation partners: English conversation partners, Spanish conversation partners, etc. More generally, I might say language practice partners.

Hope that is helpful!