I have a rabbit that is an adult now, that never learned from her mom how to drink out of a bottle, and still doesn't know how, so she has a water dish. They actually drink better out of a dish anyways. This rabbit of mine also wasn't properly weaned and didn't know how to eat grass or pellets either. She would only eat leafy greens. They didn't give her soft poops, so for the first 10 days that I had her, I was feeding her as much leafy greens as she wanted, which was a head of green leaf lettuce a day. She peed alot because of all the water content, so in a case like that electrolyes or vitamins might be needed to offset the excessive urination.
I would hold off on the pellets because he won't be used to them and it could upset his stomach if he eats them. Maybe just have like 5 pieces in the dish, so that if he decides to try them it won't upset his digestion. You could try buying a different kind of hay, that might make a difference, or maybe try mixing in a pinch of oats into the hay and see if that gets him interested. You just don't want to overdo carbs or treats as it could get him sick. Just keep some hay in with him and I think he will eventually try it, maybe as he becomes more comfortable being in his new place. Can you get any fresh grass to see if he'll eat any of that? If he'll keep eating veggies, then just keep doing that for now. I wouldn't try too many different veggies at first cause you don't want him to get an upset stomach. Maybe stick with leafy greens like parsley, cilantro, green leaf lettuce (not iceburg), things like that, and keep an eye out for any soft poops, or no poop at all. As long as he's eating something that's a good sign. Does he seem nervous in his cage, or does he seem to be adjusting to the new environment ok?
