Welcome to Thunkable!
Multiplayer games are complicated so there’s not a simple answer to your questions.
I’ve tried making a multiplayer game using Firebase to store data and listeners to check to see which player’s turn it is. This is similar to how a chat app might work. I don’t know of any multiplayer tutorials for Thunkable but you could Google that or just start with a chat tutorial because that will probably be similar. For that, Google chat Thunkable firebase.
If you get stuck and need help, focus on a specific problem/question and be sure to include screenshots, project link, and relevant details.
See this: How to ask Great Questions v2.0