You don't / shouldn't really feed pellets because they aren't too healthy for them. As long as you provide for now alfalfa hay since he is a baby. Once he gets to be a little older I would say 4 months change to Timothy hay. As long as he has constant acsess to hay he dosen't need pellet food.

If he is 10 weeks he can't have veggies yet as his immune system is not ready for them yet. start feeding veggies when he is 6 months old. The time to be fixed, you can use them as bribary to make him forgive you lol.

As for introducing him to your cats, let him get settled in first. When you bring him home put him right in his cage till the next day then take him out and let him explore one room a day. After a couple days let the cats wonder into the room and sniff the cage etc. Without bunny in it. Let them do a whole search for about 10 minutes then bring bunny in put him in the cage and let them smell the cage. Any swatting or trying to get the paws through the bar discourage immeditaly.

Just say no and maybe spray them with a water bottle. If everything gose fine then proceed to taking him out of the cage and letting them see him. If they do swat through the bars then wait another couple days and then try again and just keep repeating.

Litter training, bunnies natuarlly are very clean animals and will choose a corner to go in. Once you notice the place he picked put the litterbox there and pick up so poop's (they are just prosced alfalfa) put them in the box to help him realize. Once fixed they usually don't have any accident poo's going places. DO NOT use cat litter. Karen has said before that it can give them lung problems and if they eat it can cause big problems and blockages. I recomend Yesterday's news. Having cats I'm sure you are familiar or at least herd of this. It is safe for the bunnies to eat/chew and is very absorbant.

Make sure baby bunny has lots of chew toys. There teeth never stop growing and constantly need to be worn down by chewing. Also their nails need regular trimming like a cats everything the same applies with the quick etc.

Make sure when bunny is 4-6 months old he gets fixed. If not it can lead to alot of behaviour issues that aren't pleasant.
Example: Biting, growling,lunging,being VERY territorial especially female bunnies, spraying (males and females) , bad litter habits, and of course the cancers they can get. Bunnies are more supseptable to cancer's of the genitals then most animals wich is why most people think they only live for 4 years when they usually live as long as a dog.