Once in school I said "I got" and teacher went bonkers. In our schools we prettend to be learning proper english, which is british english, and our teachers act as if american english is just some dirty slang. So you would use "I have" to say "I own" and you can use "I got" in more relaxed conversation, or, to indicate that you received something, like trough mail. for example: I have a car, it's my second home. I got a package, and it's unmarked, I don't know what it is.

Got has a feeling of "received" to it, "I went to the store and GOT (bought, recieved) a book"

The previous responses are correct, but I wanted to add something. "Got" and "have" can be used interchangeably, only that "got" is more informal. Person A: How many cars do you got? Person B: I got 2 cars, one for me, and another for my wife.