You have a long way to go appan! First you need to file for I-140,then think of CP or AOS.
If you opt for CP and it is rejected, you cannot come back to USA. Normal procedure is that they would cancel existing visas (H1/L1 etc) unless they have good reason to give you some more time to get additional documentation to clear CP. If they decide not to approve, you cannot enter US.
Thanks,
Puliraju