Someone should point out to this young man what the word "native" means. A native English speaker's first language is commonly English, you will never have that because it's a foreign language to you. You can be fluent or good at speaking English, though. If you meant that, then basically try to practice as much as you can. Watch shows or movies in English with subtitles.

If you want to be fluent in speaking, the best advice is to listen to as much native English as possible. The key is you want to listen to material that is JUST above your level. If it's too hard, you won't retain anything, if it's too easy, you won't learn anything new

Did you mean, how do I know you are a native speaker of English? Or we would say "a native English speaker".

Practice and practice...