Looks like a beautiful cat! Three of my six are black cats.
Anyway, definitely do get him a cat tree. I have 6 cats and they all learned very quickly that they could scratch and rough house all they wanted on their cat tree but not on my furniture. Didn't even need a water gun, I would just give a loud pssst when they would scratch on the furniture and now they never touch it. They really love sharpening their claws on the sisal or wood posts. And do get him some kitty toys, preferrably some with cat nip!
I've never toilet trained a cat so I can't comment on that, for me a litter box was just way easier. And mine are indoor/outdoor so it only really gets used by my kitten who is mostly indoor.