Will this kitty be from a breeder or rescue/shelter? I think most breeder kitties are litter trained, at least mine were. I got them at 8 wks and the other at 4 months.
My friend has litter trained though, it's pretty simple. Set up a small room, bathrooms work best because they are small and easy to clean. Put a litter box (which you are to keep very clean) food and water bowls and a cat tree or scratching post. Also have some "independent" toys in their (little balls he can throw around by himself, fake mice etc.) and make sure they are safe. When you first bring him home let him out in here. Let him explore, then using the scooper or your finger (it's clean litter so no worries) start moving the litter around slightly so he gets interested. This is mostly so he knows it's there, he probably won't use it right now. I will after being home a few hours put the kitty in the box, I don't know if this is something most people recommend though. When I do it I just want to make sure the kitty feels the litter. Never grab his paw and make him dig though. On Willie's first day home I had no idea if he was litter trained I picked him up and plopped him in and on the third time he went pee for me, then he got lost of bum scrubs (his favorite thing in the whole world). If when you put the kitty in he leaps out quickly then don't do it again. In my experience they will stand there a minute before jumping out, they might sniff too, and that is what I want, I want them to be familiar with it.
Basically just keep him in the room for a week or two (or more depending on his size) and he will figure it out. Keep the box clean, clean at least once a day. Spend lots of time with him and when you see him go potty praise him with a type pf petting he likes or a treat he likes or even a fun game. You don't need to praise every time though (but when you see him it won't hurt), since cats automatically prefer to potty in sandy textured areas where they can cover the poo.
For the second question, it's also pretty simple but they may slip up from time to time. The first and most important step is find what your cat likes. My cat Neko LOVES the cheap cardboard scratchers, they are his favorite. Willie will not touch them, rope or carpet ones
so none that are commercially made. I had to make his out of an old pair of jeans, he still does not love them but he uses it, I think I'll need to add stuffing between the denim and wooden plank so he can dig in further. Anyway. fin what he likes, I here most like rope, just not mine.
Also remember the post should be taller than the cat when he stretches. Another consideration is does your kitty like scratching vertically or horizontally. Mine will do both but Willie prefers to stretch vertically and scratch horizontally so he stretches on out walls. You may end up buying many scratching posts. I'd also recommend a cat tree because they are awesome.
Basically encourage your cats to scratch it. Since he will be a kitten, catnip is useless, but once he's older you can use that and he might like it (not all cats like it though). For Neko I just plopped him on it and he started scratching, for Willie I had to play with a string on top of it so when he attacked the string his claws went into the post. Then he got the idea. With this also never grab your cats paw and make him scratch.
When you see the kitty scratching the couch stop him as quickly as you can. Make a noise to startle him and then go get him or simply go get him. Pick him up and bring him straight to his scratcher (I suggest keeping it in the same room as the furniture) and encourage him to scratch.
This is what I recommend, most people will say either a)spray him with water or b) use double sided tape. I used the spray bottle and it failed, they listened only when the bottle was present, and that was only Neko, Willie didn't care. If there was no bottle the cat scratched. Double sided tape with work (they don't like the feeling) but for us was not practical because unlike most cats ours scratched the couch where your arms rests not on the side or front vertically but actually horizontally. So if we put tape there we could not sit there either.
So my cats respond to a high squeaky noise I make. I usually do that to get their attention, then I go get them (while making the noise, stop when I get to them) and bring them to their scratcher. I also use the noise to get him to stop eating plastic bags and to stop him from going on top if the gerbil cage. Willie listens to it the best because I don't really ever have to use it on Neko.
Also if th cat is usually very good about scratching (Neko) and you see him start doing it, it might be time for a new post. Once in a while Neko will start on the couch, I go get him and bring him to his post which he scratched for a second and stops, so I flip it over (new unused side) and he goes to town.
On a final note, keep your cats claws clipped. Practice from day one cutting them so he is used to it. Cats will scratch to take of sheaths of their nails, if you slip them you take the sheaths off eliminating this need (it also hurts less when they knead or scratch you!, and when it does not hurt when they scratch you, it is easier for you to not pull away which would make the cat scratch harder).
Sorry about the long post lol, I tend to be too thorough but I hope it helped.(OMG I just deleted the entire message by accident, I almost peed my pants, thank God for the undo button)
Any way as for a list...
1.
Litter box
2. litter
3.
high quality food, preferably canned (if you don't know why I'll tell you) or both canned and dry.
4.
bowls, don't use plastic
5.
cat scratching posts and/or cat tree, don't get the ones than hang from door knobs
6.
toys!! now here's my advice on toys...ones you buy tend to break except the balls. Get the multiple different balls for independent or together play. I also get the fake mice (but Neko chews the tails off and try to swallow them so I have to cut them off
) and you can get toys on a stick but pull on them in every which way first and don't leave the cat unsupervised with them, they are for together play. You can also make a toy simply by crumpling up a piece of paper and batting it around. Just be careful with toys, If the cat can get at the bell then remove the bell. My cats like Pipe cleaners (I fold back the pointy ends and twist in into random shapes) but I don't know if they are considered safe.
7.
Brush, especially if you get a medium or long haired kitty. If he has short hair and you want to reduce shedding/hairballs then get a rubber bristle brush so it pulls the dead hair off not a pin bristle brush which just goes between the hairs.
8.
Toothbrush and paste you'll need to find a flavor he likes and start with this right away also.
9.
Nail clippers I just use human ones though
10.
Crate/carrier at some point he'll need one to travel in
That's all I can think of right now, when do you think you'll be getting one?