If you have no compression on two cylinders it sounds serious. our engines are interference engines and if the timing gears have slipped out of time or the chain has broken, you could have destroyed valves, pistons or both. If you are getting even low compression on all four, it may not be so bad.
There is a video on youtube. i think it is titled ECOTECH TIMING CHAIN REPLACEMENT that will give you a pretty good idea of what is involved.
check that compression again and good luck.