For the first week only the pellets and hay the breeder has been using.
On day 3 you can SLOWLY start adding small amounts of a 16% protein pellet to the bunnies bowl to gradually transition her to your brand of rabbit food. Don't buy the kind of rabbit chow with seeds or dried fruit in it as the rabbit will pick out these and not have a balanced diet
After 10 to 14 days the baby should be eating just your brand of rabbit food and grass or Timothy hay. If there is no signs of digestive issues you can finally start offering 1 inch square bits of fresh foods but at the FIRST sign of tummy upset or tiredness STOP and just offer hay and pellets.
During the first week you should also leave your rabbit alone! And not handle it for more than a few minutes at a time and let the baby get plenty of rest
I would never take a rabbit younger than 5 months old off my property or subject it to very much stress on my farm so no ATV rides or excessive exercise or handling
Once the rabbit is older and more hardy you can have 8 to 14 years to tote it around town - IF it is the kind of rabbit that likes that sort of thing, some rabbits are definite home-bodies and HATE leaving the comfort and security of their cage or to go beyond one room, others get down right upset if they are left behind and actually enjoy going on adventures
If your rabbit is a homebody then accept that and don't force them to go out - not moving or exploring and sitting still or acting "frozen" means your rabbit is terrified an you should put them back in their home where they can feel safe
