My rabbits are in the cave under the stairs ...they need lots of hay , mine get Timothy hay and sometimes as a treat calmomile hay.
They need lots of stuff to chew and nibble to keep their teeth down . Over grown teeth can cause no end of problems for a rabbit.
Sisal mats are good too , as they can chew them , but as they are tough the wear down claws also .get your vet to teach you how to trim claws properly . You will need to do it if the rabbits are house pets.
Hard veg is good , but mine would happily eat anything ...don't give lettuce it's very bad for them...and wash all fruit and veg first.
Also you will need to worm your rabbits , use pancur obtain it from vet . They need injections 6 monthly if they go outside or if they will be in contact with other animals who do.
You can get special rabbit toys from pets shops , mine love their little wooden house for hiding in , but you could happily give them a cardboard box to play with / chew . Rabbits can be quite clever at finding treats if you hide them inside boxes /tubes . Any toy that mimics natural environment (burrow like) is good ....tunnels , boxes to hide In .
And you will need to neuter them , so you don't have them fighting , or end up with loads of baby rabbits !