I have a disk pushing on a nerve in my neck an my trap an back is all knotted I have a appointment wedsday to see a neck doctor should I get cortozon.?

Maybe. More info. . It is possible that a cortisone injection may be helpful but more info is needed before a definite treatment plan can be recommended. Things to consider: how far is the disc herniated? Weakness to the arm or hand? What else has been tried? Relief with medications? Physical therapy? How long with symptoms? Lots of questions need answering before an injection.
Maybe. If the doctor thinks that a cortisone injection would give you relief there's nothing wrong with trying at least 1 injection. Just make sure the doctor is well trained and does the procedures under x-ray guidance. Pinched nerve in the neck often causes pain in the shoulder or upper back.