I’ve owned lots of cats (and bred for a while) and they’re actually pretty simple creatures 😁 my recommendations as follows:
Hooded litter tray with swingy door for privacy and stopping litter flying everywhere
Van Cat cat litter, this stuff is amazing, the clumps are like concrete, you just get a litter scoop (I find one of those big kitchen spoons with holes in actually does a better job, wee clumps don’t roll off it) so as long as you pick out the poo and wee every day, you hardly ever have to do a full litter change.
https://www.vancatuk.com/
Cat beds - have never had a single cat sleep in one
Cat trees - cats largely ignore
Scratching posts - largely ignore, but have one from Amazon that current cat actually uses! Keep it simple
Dishes - ceramic or metal, plastic harbours bacteria. Ours has a water fountain but the filters are costly and I sometimes wonder why I bother when I catch him whiskers deep in the depths of the toilet bowl…
Dry food is better for their teeth depending on brand etc, be wary of sugary wet food
Toys - ours does enjoy catnip mice with proper catnip, but nowhere near as much as pipe cleaners, ear buds and twisty ties off cables… does love his laser pointer - cats adore these, don’t shine it in their eyes and don’t go on for too long, cats only have short burst energy and can get too tired
Collar - make sure it has a quick release and/or elastic so that your cat can twist itself out if it gets caught, this happens more often than people think 😭 reflective strips and a bell to try to limit sad squashed bits of wildlife around the house!
With an outdoor cat, I’d always advise keeping them in at night before it gets dark, and only letting them out once it’s light. Seems harsh given that their favourite playtime is dusk and early morning, but these are also the most likely time for them to get knocked down, even on the quietest roads 😢