Firstly,hello everybody, i'm new to this!! I basically joined for some advice about my young cat,so here goes..

we've recently moved house from a second floor flat (where Pancakes (my cat) was an indoor cat) to a place with a garden where we eventually want to let him out. I've read a lot about how to go about this and something said to shoo any other cats out of the garden to help your cat gain his territory. however, there is a cat who is friendly with me when outside and will come up to me for fuss, and recently he's been coming to our patio doors in the morning and sitting opposite pancakes (who sits on the other side of the window) and just look at each other..sometimes putting their paws on the window..not in a threatening way, just gentle scratching.should i leave these cats to look at each other or should i shoo the other cat away?? I will be very greatful for any replies,
the new kid on the block =)