I think you first need to just read articles on the Internet about how game companies build level generation. What principles and laws do they use. There are many such articles. I am sure you will find many useful solutions and get new ideas.
If you have been registered in the Epic family for a long time and keep track of the set of assets that they give away every month, then look at your library, maybe you have a “Procedural Level Generator”.
*it was given away for free a year ago. You can also write to the seller and ask how he implemented and came up with it. Here is his mail zegi.diablo@gmail.com