Vic and Lil’ Bob came as a pair (brothers) to us when they were about a year old so past the kitten stage. As well as what’s already been said by others I can add from our experience:
1) They were very nervous when they arrived and hid behind the sofa at first but they soon started to get curious and went around the house “marking” everything and establishing it as their home.
2) They’ll work out where they want to sleep and it’s almost certainly not going to be the cat bed you bought them! Our two slept together at first (safety in familiarity) but soon found their favourite spots and still sleep near each other most nights. If there’s a bit of friction, try stroking one before stroking the other with the same hands to transfer and mix their scents - good for “community cohesion”
3) Keeping them in until they’ve got a sense of ownership/home is a good idea and best to operate an “airlock” system when entering or leaving the house with one closed inside door between them and the exterior door. Stick up a few notes at eye level to remind guests (& yourself) to do this and you shouldn’t have any premature escapes. When you do let them out for the first time, send them out hungry and go out with them so they can see you and it’ll remind them who feeds them!
4) We just gave them one litter tray between them and that worked OK. Once they had their freedom and could come and go as they pleased (microchip activated cat flap) they wouldn’t dream of crapping in the house again.
5) Separate food and water bowls are a good idea.
6) Buy some ping pong balls, string and catnip - most cats are helpless against their powers and play helps them bond with you.
Good luck with your new arrivals
