Last year I took my own practice tyres, and practiced for two days on them.
Actual qualifying and race tyres were purchased at the event as required (as part of entry), then assembled/glued in front of scruitineers and marked as required.
The actual qual/race tyres were handed out and returned each day. We also had the opportunity to purchase/collect an additional set of tyres if we made the A-final.
Was itching to come this year but other commitments have come my way, I'm sure everyone will have a great time!