2000 Chevrolet Blazer Yr Bought Because Intake Gaskets Went Bad Let Water Mix

I have a blazer yr 2000 and i bought it because the intake gaskets went bad and let water mix with the oil. so i bought a gasket set. i flushed the motor out put new push rods because of surface rust put it all back together and wen i went to go start it. the motor turned over insted of it making a ra ra ra ra and starting up it makes a wine. someone told me to do a compression test because the push rods have been replaced and maybe pumped up. what does that mean? I dont know much about cars please explain better.