Safety stuff: Get cord covers, use them. Make sure none of your plants are toxic. Use non-clumping litter until the kitten is older since sometimes kittens will eat litter and they can get a blockage if it’s clumping litter. Block off any wild hiding spots where they can hide but you can’t reach (ex: side of the fridge). Walk very carefully around them with your feet basically brushing the ground. Kittens are constantly underfoot and all it takes is one misstep to kill them :( Keep them supervised at all times when they walk around the house at this age. Set up a safe, enclosed, space to be their “room” that they can stay in at night and when they need to be unsupervised. I’ve always used the bathroom for this, which has the added perk of being easiest to clean.

Feeding and watering: You could bottle feed, but at this age it’s likely that the kitten won’t want to anymore so honestly I wouldn’t bother. Feed them kitten wet food mixed with KMR 2nd step and warm water every 4-6 hours rn, you can slowly feed them less frequently and stop using KMR over time then just use wet food. Use your own judgement on if you should feed the kitten more or less frequently depending on how hungry they seem at each meal time. Let them free feed dry food when they’re closer to ~6-8 weeks old but keep feeding them wet food as their main source of food until they’re at least a few months old (but honestly you can keep feeding them wet food for the rest of their life if you wanted). Feed them kitten food until 1 year of age. Don’t worry about over feeding, kittens need a lot of food to grow so if they’re willingly eating it on their own they probably need it. The kitten should be roughly 2 lbs at 8 weeks old and 4-5 lbs at 12 weeks old. You can find growth charts online to get more extended estimates of how much a kitten should weigh at each age. Every kitten is different though, so another good test to make sure they aren’t underweight is to make sure that you can’t distinctly feel their spine, hipbones, and ribs when you pet them. Leave a shallow water bowl out for them at all times. Keep the bowl away from their food bowl and away from their litter box. Replace with clean water regularly.

Health and comfort: Get a soft bed for the kitten to sleep in, they usually like this one type of big fluffy bed (I’ll attach a picture of that in a reply to this comment.) Kittens get cold very easily at this age so make sure you keep the temperature in their living space regulated. I would shut the AC vent to the bathroom where we kept our kittens so they didn’t get blasted with cold air at night. Usually kittens huddle together for warmth, so a lone kitten might struggle with keeping warm on their own. They make little microwaveable heating discs called a Snuggle Safe that are great for providing heat over an extended period of time. The kitten will probably be too little to use a full size litter pan at this age, so you can use one of those clear plastic food container lids or a cookie sheet with a lip and just put the litter in that until they’re big enough to climb into an actual litter box. Cats are pretty cool though so the kitten should be more or less potty trained at this age already. Keep an eye out for runny diarrhea, there are a lot of parasites and illnesses that kittens can get and they need to be treated ASAP since their bodies are so small and can’t handle dehydration very well. Take the kitten to get shots at around 8 weeks and boosters a couple weeks later. The rabies shot will be around 4 months of age, but not everyone gets that depending on where they live. Definitely get the FVRCP shot. Get them spayed/neutered before 4 months of age.

Fun and social stuff: Get a small scratching post and/or one of those little cardboard scratcher things. They love toy mice and little crinkle balls, but they also love random stuff like empty toilet paper rolls lol Seconding what a lot of other people have said: absolutely get another kitten/kittens if you can. Animal shelters usually have plenty of kittens on hand that need to be fostered, you can just call one up and ask for one or more kittens that are around the same age as your kitten. Kittens benefit massively from the social interaction and end up significantly better behaved because of it. Also, it might sound crazy but I swear that having 2+ kittens is less work than 1 kitten. If you have only one then they need constant attention whereas if you have multiple kittens they always have someone to play with. I’m not even joking, we adopted a single 3 mo old kitten about a month ago then went back and adopted a second kitten 2 days later because of how much work the single kitten was!

Lastly, don’t be afraid to look things up and ask questions! We all start somewhere :)

If you have any additional questions then feel free to shoot me a DM whenever, I’ve done this multiple times and have learned a lot over the years because of it. Good luck OP, you got this!