What if I only want to babysit cats? or care for homes while people are away (water plants, mail)? do you have that capacity?

On your service page of your profile, you can indicate which services you want to offer. If you only want to offer House Sitting, turn the others off and you won't show up in searches for them.

Many Rover sitters only care for cats. When you build your profile you will state that you only care for cats, and you will only select the services directed toward them, home siting or drop in visits. Your profile should also contain mostly cat pictures. Best of luck