All the nurses I've ever worked with have been lovely. One was a bit brusque but that was just her manner and she didn't mean anything by it. They're people like you'd find in any other workplace - some you'll get on with, some you won't. I wouldn't set too much store by horror stories on the Internet. Lots of people like to complain about a bad workplace online, as a vent, but far fewer people are going to log on and announce how much they love their job - they don't have the same motivation to do so!
My induction and training involved basic First Aid (CPR, what to do if someone goes into anaphylactic shock, etc.) and an explanation of the ward policies and procedures (this was a mental health unit so they described what to do if a patient is hurting themselves, how to respond if someone discloses abuse, etc.). The details of your training will depend on what sort of ward it is but you won't be expected to learn everything at once - you will pick up a lot as you go. I know most HCAs on our ward were taught how to take a blood pressure reading after working there for a while, for example, but this wasn't included as part of the induction.