How to care for rabbits?

I recently inherited a rabbit from an elder from my community who passed away. The rabbit i inherited is a male lop bunny. The bunny came with like next to nothing except a cage. I don’t really know how to care for it? What foods it can eat? I have ordered bedding and plan on ordering a bigger cage. I was unaware about receiving this bunny, my aunty just came and brought the bunny to me and said it’s mine now and left. The rabbit is about 5 years old, it was very close to his owner, at the funeral the bunny didn’t leave the owners side the whole time.

He’s eating and drinking okay, but I’m worried he may be grieving and depressed? I’m not too educated on bunnies, so I’d appreciate any advice, tips, and what not to make the bunny feel more comfortable and happy:) please help