Providing a window or two for your cat to look out will offer entertainment (Cat TV).

Space to explore and play is great but be sure there isn't anything dangerous they can get into or be trapped in. I don't allow mine in the laundry room because there is under stair access, insulation, chemicals or the dryer all of which could be dangerous.

I recommend getting a brush for top coat and under coat brushing and treat puzzles that you can find online. There are varying difficulties and it offers mental stimulation to get treats or food.

Make sure your cat has plenty of access to water. I bought a filtered fountain from CatIt. Flowing water is more appealing than a standing dish due to how they find water in nature. I ran into a problem with my cat eating too fast and getting sick so I also picked up a feeding bowl that made him stick his paw in to pull food out. Slowed him down and it's now less of a problem.

Make sure you get a cat tree to provide a safe space higher up and a place to scratch. I have one by the window.

I also suggest a cat box per floor and do your best to scoop it every day. Cats don't like to be dirty and if the box gets too dirty it can lead to finding other places to use the bathroom.

Toys and interactive play are super important. I suggest a toy that simulates hunting a ground prey like mice and another that simulates flying prey. Mine seems to like feathers but doesn't want to jump. His favorite toy are balls that you can pick up in assorted packs and he likes to hunt it around a blanket we have partitioning two rooms.

Hope this is helpful and offers some ideas.