There's no way you need to rebuild your engine after this. Maybe you have bent a valve or two or more, but you haven't been whaling on the car, just trying to get it to turn over, right? I don't know exactly where the timing should be set. I'm sure you can find it. Did you not mark on the belt where it was when you took it off?

 

Yah I was only trying to start the car, after changeing the belt.
I did mark it but when I put it back together it would only turn over, not starting.
Then I started to F with it and now it sounds like it is not making eney compression.
How much are valves? should I upgrade if I do need to change them? if so what ones should I get?
I have an 02 A4 tip with Revo K-04.

 

Well maybe i'm just talking about mechanics in Australia, but the cost of changing vavles and repairing any damages is more expensive than rebuilding the top end (new head)

 

I would suggest not doing anything further with the engine and take it to a mechanic before you do any more damage.

 

In your case I think this may be the best option. Not having a crack, just think without seeing or hearing, we are all given advice blind & deaf.