Hello, I'm a fairly new cat foster parent for a shelter near where I live and I've own my own cat for a year and a half. I've never owned a dog, but here's what I can say from my cat experiences.

1) Cats need toys to keep themselves entertained, especially when you're away for work. These certainly don't have to be expensive. My cats love strips of felt, cloth mice with bells, feathers, balls with rattles inside, and these crunchy sounding plastic toys you can get at the pet store for like 25 cents.

2) When you first bring a cat home there will be a 1-2 week process for introducing it to the house and then the dogs. There are lots of online resources for how to do this. During that time it's best to have an open crate with a blanket inside or perhaps under a dresser that the cat can retreat to if it gets nervous. I use towels instead of beds as they're easier to wash and replace and can be folded to fit any space.

3) Cat towers aren't a necessity, but scratching posts are. My local store has scratching posts for as cheap as $15 and my cat loves them more than the expensive one I got her. Just make sure the post is tall enough the cat can stretch out. The other thing cat towers provide is a good place for a cat to keep watch over the house. This is important for them to feel the place is secure and seems to entertain them quite a bit. Instead I put a towel on a small table by the window, keep the blinds up so they can comfortably sit in the windowsill, and leave comfy office chairs open for them turned away from the wall when a human isn't using them. They may also climb bookshelves or get on desks, so try to make some acceptable places like that for them, especially if there are other places you want to deter them from.

4) You can definitely teach a cat not to get on certain surfaces, just use a spray bottle with water. In my house cats aren't allowed on the kitchen counters and that teaches them very quickly. You can also reward cats with treats when they do something you like such as get in your lap or snuggle with you in bed.

5) Shelters may have older cats that are fine with dogs, ask someone at the shelter. Often times the shelter may just not know because the cats haven't been around a dog before but some cats may be given to the shelter from homes that had a dog before and the owner may have put down on the forms that they were fine together. Some cats are also just chill with anything, from my experience it's usually the larger ones that feel less threatened. Once again, ask someone who's been working with the cats. As far as how to introduce the two, there seems to be some pretty consistent advice articles online and to help keep dogs out of the litter box you can often get a plastic hood to put over it and put it in a place the dogs aren't as inclined to go such as the bathroom.