Someone give me an idiot's guide to X boxes?

[ohtsmeagain]

Hi,
Finally succumbing to pressure to buy a console. Can you lovely MNetters help me with a couple of questions please for an Xbox Virgin?

I have bought one all digital x box series S so far as that is all I can lay my hands on. Think I might need a second console and don't know if I need another digital one or one that you slot actual hard copy games into?

1. Have two teens. Each with their own mates but would also want to play games against each other in live time. How many consoles do I need? Two? If so, do I have to purchase the games separately for each child?
2. Should I buy another series S? Or get one second hand that comes with some hard copy games?
3. In either case, is there any way I can get away with buying one copy of a game only? Eg one copy of FIFA 22? If I buy it digitally, can the other console get their own profile on it?
4. I have two cheap and cheerful TV sets. Is that what the x boxes plug into? If so what lead do the TVs need to accept?

Help! I'm so stuck!