Yes. You can set up any position in an unrated game and make it the starting position.
https://support.chess.com/en/articles/8597997-how-can-i-play-a-game-from-a-custom-position
The classroom feature might help you actually chat and discuss the positions.
https://support.chess.com/en/articles/8708915-how-do-i-use-classroom
Hi, I would like help a friend practice set positions with. Is there a way to preset the board and then challenge them so that we can play?