Welcome to Rabbits United
This forum offers a lot of support and advise, I'm sure you will love it.
Make sure the cage is massive and give the bunny the freezom to run around the house when supervised.
I have a house rabbit and our bond is so strong because we let him run around the house.
The main part of a rabbits diet is Hay.
Give the bunny a hand and half full of pelets (I give my rabbit Bugess or Harrigtons) in the morning, but mostly hay and the odd treat during the week.
I clean my rabbit out every 3 days and provide lost of fresh hay.
He is in his cage at night but free in our house or garden whenever someone is there to supervise him (there is almost always someone there).
I wouldn't leave the rest of the cage bare, you want it to be cosy for the rabbit so just make sure there is a lot of hay in there, you can also get little rabbit beds.
I would also advise getting him checked out at the gvets as soon as possible and get all the booster injections early on to prevent illness.