'Wanna' is slang for 'want to'. People say 'wanna' all the time in casual conversation, but don't usually write it. Ex. Do you want to go to the movies this afternoon? Do you wanna go to the movies this afternoon?

"Wanna" is slang for "want" or "want to". Don't use it. It sounds like something a little child would say.

When you use 'wanna' you don't use 'to'. It's a informal way to say 'want to'. I'm learning too, maybe a native speaker can explain better.

Good question and wonderful answers! I 'wanna' note them down. Haha

The question was not "which pronunciation should a learner learn first," but what is the difference between the two. As to insisting that learners "should" learn "want to" first, and then learn "wanna," I disagree. I think it depends on the learning environment, the reason the learner is learning English, the language faculty of the student, and other factors.