Are you supposed to know everything after nursing school?

The answer is no, yes, and maybe.

No: You have no experience yet, so you can't possibly know everything, and it's not expected that a newly graduated nurse is perfect 100% of the time. And, if you act as if you do know what to do all the time, the staff probably won't like you and would be wary of your nursing skills. Acknowledging you don't know something is a good way to learn and grow.

Yes: You do need to know when your patient is not doing well. They teach that in nursing school. Remember to start with the ABC's. Know your normals for vitals. Know the progression of the disease or ailment the person has. Know the common risks of the operation that the patient just had. You do need to know a lot, and you'll probably be spending a LOT of time learning it all both at work and on your own time. Try to look things up on your own before asking. If you don't have time and the patient is going sour quickly, ask your charge nurse or a more senior nurse NOW.

Maybe: You do have a license to defend. Work within your scope. Ask questions. Acknowledge you don't know something and LEARN IT. Don't settle for "that's the way its always been done". I catch myself sometimes with that. If it's an emergency and you don't have time to learn to do things or about the drug before you have to prepare it, and the MD and a more senior nurse is guiding you through the process, quickly scan the details so you prepare it properly, and then GO BACK AFTER AND LEARN WHAT YOU DID.

I'm no where perfect and I'm still learning ALL THE TIME. Something new comes into the ED everyday, and I find myself overwhelmed at times. I try to take it in stride, and read up on things afterward. Also, if you have a nursing friend you can trust, run it through them and your fears. They probably feel the same way.

Good luck!