Re: I feel so incompetent....
I'm sure you're not the only who feel unprepared for the "real world."
It seems to be an unfortunate trend in nursing education to reduce the students' clinical experience. Even if a program may provide lots of hours of clinical time, it may be with only a few patients and only covering a small portion of actual nursing duties.
So then hospitals are having to supplement nursing education by offering longer orientation and preceptorships. During this time, the new grad is usually paired with an experienced nurse they split the care with the newbie taking on more and more over time.
I'd figure the longer the orientation, the better. Standard is probably 6-8 weeks. A local hospital I know of offers 4 months, but you need to give a 2 yr commitment or pay back the hospital for the training time. I've heard of as long as 6 months for specialty areas (eg. ICU).
So if you're feeling particularly unprepared, don't settle for taking any old job offer. If they're going to throw you off orientation in 3 weeks, that's not a good sign of how they support new grads. Even then, you can't know everything about a facility or about how you'll do, so if the first position doesn't work out, count it as a learning experience and try again.
If you have any access to your school's previous graduates, ask them about their experiences with orientation and local facilities.