How to store player stats in multiplayer travel?

Hi, i am making a multiplayer game and between each round i travel between a Shop level and a level which you fight in. My problem is that i need to store information about each connected player. When a round is over every player travels to the shop level to buy items but i can’t figure out how to store the items of each player between the levels. Right now i am trying to use the game instance and an array of owned equipment’s but i can’t tell which player the equipment’s belong to.