Stuck in kingdom hearts?

I beat all the bosses at the first 4 worlds now I'm stuck. At the collesium Phil keeps saying he has to clean up for the games and asks if I want to practice on the barrels which I've done about. 4 times already. I talked to cloud and got the ticket from hades. As I sai I can't find anything else to do in the other 3 worlds. Do I jus fight heartless and level up to make something happen?