Rabbits love to eat fresh fruits and vegetables. Carrots are a good choice, but you shouldn’t give a rabbit solely carrots. That’s detrimental to their health - as is when a human eats only one thing. However, a rabbit’s diet should mostly be hay. This should be Timothy hay or meadow hay if possible, but if not another kind of hay will do.
If you do decide to give your rabbit fruits and vegetables, there are a few that are completely safe and are always good if you can’t decide. A few of them include carrots (but not the roots), courgettes, pumpkin, red peppers, romaine lettuce, grapes, mangoes, melons, and bananas. There are others, but always do your research if you aren’t sure if a food is safe for your rabbit.