Multiplayer On One Device

Hello i am trying to make a game where they enter the amount of players, amount of rounds and then each play gets a turn and the highest score wins the round .can you please assist me.
Thank You

I’m only new to Unity also but I’m going to say that the more experienced who are going to help you if they do probably won’t help you do this whole section for the game as it would take a lot of time you would be better to ask more specific questions for specific problems you encounter