Hi. I also have never had a rabbit but I did work at a pet store and learned some pointers...first off, don't feed her/him any celery, it's too high in water content, also you should stay away from head lettuce (Iceburg) also because it's very high in water content and low in nutrition. If you feed him/her greens try to feed her dark green greens (parsley is great, spinich). Carrots are great. Her/his stool should be firm, not wattery. If it's wattery cut out veggies for a few days and feed strictly pellets and maybe add in some whole oats. They are pretty easy pets, there's not too much to it I think you will be a wonderful new bunny mommie

Sorry but I don't have any more advise. Good luck to you and your new bunny