Question

Whats the difference? tu vs toi. What's the difference between the two?

Answer 1

Tu : is a pronoun (je,tu,il/elle/on,nous,vous,ils) and is only used before a verb. ex: Tu manges des tomates (you are eating tomatoes)
toi: when you want to say "you" and there is no verb before or after.
Toi, tu pars à 10h (You, you are leaving at 10am)
I hope hope this makes sense to you (i am bilingual so this should be right lol)

Answer 2

You and you
I think it is just the way they are pronounced probably
One is a pronoun=toi and the other is an adjective=tu