To get a 2 combo from 1 pass, follow this. Hold forward, the right anolouge stick, and L1. If it is a successful pass then your player might do another combo which will always work.
(This won't work every time but it does most of the time)

You have to collect 50 cards to unlock the Bulgarian World Cup Quidditch Team.

Beat the Hogwarts Cup with any team you want to unlock the World Cup.