Where can I find my party invitations on Steam?
Outstanding Steam party invites will show up in the Steam overlay (shift + tab). If you accept an invite, you will immediately join that party’s existing game.
If you have Steam friends who are online and in Streamline parties that allow Steam friends to join, you will see a “FRIENDS” button on the home menu and the number of friends you can join. Clicking this button opens a display that gives you a list of options to join your friends’ parties!