You can either make a new place in the starter place - and have that be the second game.
You’re only other option really is to use badges. I can’t think off of the top of my head, a way to make read data from completely different games.
Your best bet is to make a place inside of a starter place for one of the games, and have it teleport to there if you join the other starter place.
You’ll have to set up an external server for this if it’s absolutely necessary they stay separate games and you need data to be accessed between those games. There’s various threads around the DevForum regarding cross-game data that you can reference for guidance.