My advice is do your research and be particular about where you do your critical care internship, if you are determined to do this straight out of school. Not every facility is set up to mentor you in ICU right out of school. A large facility with a dedicated new grad internship with a solid critical care internship program with ongloing support is your best bet.
For every nurse who tells you they went right into critical care and 'did OK" , there are just as many who were thrown to the wolves, used as a pawn as a 'warm body' in ICU, left floundering ....in the wrong ICU this situation is stressful on the new grad AND experienced critical care staff.
In the ICU's I work in, there is not an adequate support system in place to accomodate a new grad's learning needs, thus a year experience in a stepdown or medsurg is a basic requirement to be considered for critical care...for good reason.
I'm not saying it can't be done, but please consider the facility carefully. Good luck to you.