Imur, welcome to the world of cat lovers!
Cats have different personalities. Whether your kitten would benefit from a companion or not depends on its personality. Billy may be sleeping the day away because he's so inclined or because there's nothing else to do.
The only single cat that I've had was completely neurotic. I loved Fitz and he loved me, but if anyone else came into the picture -- look out! The vet had to handle him with falconry gloves, and we had a warning from the mail carriers that they would stop delivering mail to our address until we restrained our cat. I often wonder if he would have been better for some cat companion (or we could have had two holy terrors on our hands!).
I currently have 3 cats, and here's how it happened: MacDuff's mate died, leaving him the sole feline in the house. Shortly after, on a bitterly cold January day, a little fluffball with a damaged tail appeared on my front porch. Gracie, as she was called, is very nervous around humans (something about the tail which had to be removed, I believe) but loves other cats. Unfortunately MacDuff did not take to her, especially with her habit of playing leap frog on his head every time he started to eat.
I had to go away for an extended business trip. I knew from past experience that MacDuff would be fine with minimal supervision, but I felt that Gracie needed more care. So I took her to a cat hotel (yes, I was surprised that such things exist, as well). The cat hotel was in fact the money-making side of a rescue agency. About half the cats were "guests" and half were feral/unwanted rescue cats.
During her stay Gracie bonded with one of the rescues. After some dithering (I did NOT want 3 cats) I asked if I could "try" the rescue at home and see how the 3 got along. It was perfect -- Babu (as the rescue came to be called) kept Gracie busy in play, but was calm enough to suit MacDuff. Peace and harmony ruled again in my little kingdom.
So, if possible, you might want to try that -- rescue agencies or Humane Societies, etc. They may allow you to have a guest, with no commitment on your part, and see if Billy likes it or not.
BTW cats do
sleep an average of 18 hours/per day -- depending on the species. Normal run-of-the-mill tabbies and Siamese are usually more active than Persians and Russian Blues, for example. Most cats, house or jungle, are active at dawn and dusk (when the prey comes to the watering holes).
Multiple litter pans will reduce the number of times that you need to clean them. That's a bonus in my eyes! :wink:
Food: Unlike dogs and humans, cats are carnivorous ~ they absorb their essential nutrients from meat. The problem with dry food is that it's mostly wheat -- carbohydrate of no nutritional value for the cat, but potentially fattening. Kinda like us and potato chips.
The best food for them is a well-fed mouse -- mostly protein, bones to crunch and clean the teeth, a little vegetable and grain from the mouse's dinner. Since no pet food company will can a mouse, the next best (according to my vet) is a balanced high-protein wet food and a handful of dry each day. And plenty of fresh water.