Do press ups get rid of man boobs and give you pecs?

Slightly not really : By increasing muscle mass, it may displace the overlying breast tissue and fat to disguise or lessen the appearance but it will not effectively reduce the excess breast tissue which must you ally be removed with surgical techniques.

Man boobs: Will not disappear with all the exercise you could possibly do. You must first find out why you have man boobs. If treatable without surgery, that is always preferable. But if your man boobs are simply there and you're in your 20's or older, you are likely going to need a surgical procedure. See your local plastic surgeon for further advice and information.