自分自身を紹介 --> 自己紹介[じこしょうかい] (self introduction) 

ぼくはハセベです。ブラジル人で、日本語の学生です(or 日本語を勉強している学生です)。は英語を話します。
*You can't use only the particle は at the top of the sentence. It should be omitted or with 私.

*I imagine from 日本語の学生です that you mayor in Japanese language. 

*I would say 英語が話せます when I talk about the language which isn't my mother's toungue like "I can speak". 

Good job! Please keep up. I hope this helps you. Muita sorte!