I Need Some Help.

"Hi everyone! My name is Ewerton. I'm Brazilian. I live in a city called Cambé in the state of Paraná. I'm 31 years old and I have a doctorate in math. I am a math professor, not a professional Portuguese teacher. But as a native speaker of Portuguese, I can help you to improve your Portuguese. I have been studying English on my own, and I know how much important it is to practice speaking as soon as possible. I like to talk and to get to know new people, and I would like to share some of the Brazilian culture with you. Since I am not a professional teacher, I don't focus in grammar rules in my classes, but rather on conversation. In this way, I can help you to improve your accent so that you may sound more like a native Brazilian Portuguese speaker. I focus on the Portuguese language spoken in everyday life. The more you practice your speaking, the more confidence you will be. Do you need any help? I am here to help you. Hope to see you soon!"

I just want to say that a lot of the corrections I made were not necessarily because it was wrong, but just so that it flows better stylistically. I did this because your English is a very high level, so I am really just picking at the details. Some things to know though is that the phrase is always "on my own" not "for my own." Also, languages, nationalities, and countries like Brazil and Portuguese are always capitalized. 

I Need Some Help.

(Part 2.  This is posted separately because iTalki's character limits are reached extra quickly when corrections include changing colors or fonts, using strikeouts, etc.) 

(1) You can say "on my own" if your meaning is "independently" (learning without a teacher or a class).   Or if you meaning is "I myself (I personally) have been learning English", then I think it will be best to simplify this and just say, "I have been studying English and I know how important...")

(2) "professor of math" is correct.  I suggested "math professor" because it is the way we usually say it in the United States.  (Perhaps other English speaking countries often say "professor of _____", so this is just an opinion of what sounds most natural to my ear.  Both ways should be fine). 

(3) may changed to can because "may" sounds more tentative..."can" sounds more optimistic, more confident

(4) native speaker of Brazilian Portuguese  (I changed the word order and put "native speaker" first since it seemed to be the key idea to focus on).

Please feel free to ask me anything about any of the suggestions I have made.  And best wishes to you with becoming a tutor here on iTalki!