Litter training & vets
CAGE AND MINIMUM SIZE
Rabbits do best in something that is at least 10 square feet, but I recommend 15 sq ft or more. I use 16sq ft (4ft x 4ft) dog exercise pens, but you can use NIC Grids, a large dog crate, a DIY cage, or you can free roam! Inside the cage, you will want two bowls for food and water, one or two litter boxes, two hides, and lots of toys for your bunny to play with. These are the minimums, so you can always add more. Make sure not to clutter the cage too much so your bunny still has room to binkie and do zoomies!
BOWLS AND LITTER BOXES
Your rabbit will need at least two bowls, one for water and one for veggies/pellets. I would reccomend getting ceramic dog bowls/crocks for your rabbit. Plastic dishes will just get thrown around and chewed. Metal bowls are the easiest to clean, but your bunny will most likely throw it around and dump it. Litter boxes can be anything, but I reccomend buying cat litter boxes. They are usually the right size (unless you have a large rabbit). The best litter, in my opinion, is paper bedding, but you can also use aspen shavings or pelleted litter. Do not use pine or cedar shavings, or clay and sand cat litters. Stick to all natural litters for rabbits. The one exception is adding a puppy pee pad below other litter to make cleaning easier. Also, make sure to add hay in/above the litter box!
TOYS AND HIDES
There are two different types of toys for your bunny. Chew toys are the most important and are the only type you need. They should be edible, usually made from hay, wood, and sisal. The other toys are not edible. They are pull-throw toys made from metal or plastic. Plastic toys, like cat balls with bells inside, should only be used when supervising your rabbit. Hides should be dark places for your rabbit to hide. Some are made of straw, hay, wood, and plastic. You can also use elevated dog beds and covered cat beds. Hides with two entrances are usually the best, so your rabbit doesn't feel trapped. An easy cheap hide to make is just using a cardboard box and cutting two large doors in it.
The best option, in my opinion, is free roaming your bunny! You don't need a cage, so it doesn't take up any space. you will just need a couple of litter boxes and hides around your house/room. You will have to make sure that all cords and anything you don't want to be chewed is out of your rabbit's reach. There are lots of youtube videos and blogs about rabbit proofing online.