Can someone tell me what's the difference between "I got" and "I have"?

I have is the correct way. I got is usually incorrect grammar.

"I got" means Ты recently recieved it. "I have" means it has been in your possesion.

If Ты ask a waiter in Лондон if Ты can get a drink, he will tell Ты to GET it yourself.

Have is a еще polite way. Get is usually used in a different, but similar, context.

Have is present tense. Got is past tense.

Sure!

I got is spelled:
I (space) G.O.T.

I have is spelled:
I (space) H.A.V.E.

They're different words.

"I got" means Ты received it.
"I have" is something Ты recently have in possession.