How do I make it so when a player enters a door, they travel to a random level?

I’m aiming to make an anomaly type game, so when the player goes forward through a door they enter a random level. I have many levels made and I want it to choose from those. I have the trigger box, but I only know how to make it go to one specific level instead of choosing from many. I’ve heard about using an array but I keep messing it up so I was wondering if anyone could help.

Also, how do I make it so once they see that level, that specific one doesn’t appear again to stop it from being repetitive?

Make an array of level object references(better yet soft references), get random, async load asset, open level by reference.

Alternatively you could look into level streaming, and have all the levels in one streaming level. And just have an array of locations preset as the various levels start point. Use the above execution chain except use set location on the actor instead of open level