:wave: Hi and welcome!
Add photo's when you get him/her. Where are you getting the bun from and how old will he/her be? If they've already been an indoors bun then you won't need too many tips.
How exciting.
I have a house bun. There's heaps of things to talk about re. indoor bunnies but immediate tips would be: cover/hide all wires and anything else which could harm them. Watch for any flowers/plants that are within reach as some can be poisonous. If you're female, hide your best pair of shoes and bag (my sister did not when she came to visit. Bad times).
If you're getting a baby or what was a previously outdoor bun then you might need to do the whole litter training thing. See where they like to go and then put the litter tray there. They tend to like them opposite the hay rack as they're v capable of doing 2 things at once!
We have an indoor cage containing hay rack, toys, water bottle and litter tray. This is just his 'feeding' zone. After we did the whole initial introduction to the flat when he was a baby, (over a period of 2 weeks - letting him out in the morning and evening but locked inside whilst at work) he became a very happy free range bun (our carpets however took a bit of stick....he was a digger for a while).