In a lot of ways, their personalities are sort of ingrained, from what I know- a snuggly bunny will be a snuggly bunny no matter how you raise it, for example. Potty training is not too hard, however, you have to be super diligent about it at first. Every poop or pee mess should be put in the litterbox, and definitely give a treat for pottying in the litterbox each time. Sometimes, in my personal experience, a rabbit will simply decide to use one spot as a bathroom, and putting a litterbox there fixes all of the issues.
Another thing to consider, is spaying. That will, in most cases, reduce aggression, urinating outside the box, and improve health and longevity once she gets old enough. It's not cheap, but well worth it in my opinion (it often doubles their lifespan!).
In terms of nutrition, they should get (again in my experience), unlimited pellets until about 6 months old. Depending on the breed, the amount of pellets will differ, but a general rule after 6 months old is 1 tbs/ 5 lbs of bunny. At this point, you should start to introduce fresh greens (I don't like to do it younger due to the risks of GI upset) very slowly (1 new green/week) and if she has diarrhea, remove them for a short time. She should have unlimited hay (not alfalfa, generally- again if she's a giant breed, this may be different), for her entire life.
Sorry if you know a lot of this already, just figured I'd offer everything I know- which is not much, since all of my buns come from shelters off of the kill list. XD