If you would like to practice with a native speaker of American/US English, you can search for tutors who speak English from the US.
But just a word of caution: it's possible to guess and understand what you mean by "a Native American speaker" here on iTalki, but the term "Native American" has a particular meaning in US English.
It means the native or indigenous or first peoples of North America who live in the US.
So you just want to be clear in your meaning. Saying "native speaker of American English" avoids that confusion.
Hope that helps! :)