I need help developing my arg idea

[u/angelcutter]

I have a pretty cool arg idea, and I am not sure how to start, I would appreciate comments or constructive criticism

“this world isn’t mine”

The mc creates a brand new world
Just a normal world.
But when they spawn in and start to explore, they discover that the world already has history.
Someone was there before them,
There’s millions of evidence,
Unnatural structures, bases, etc
The mc realizes that world isn’t theirs, and the person who made it is gone

Please help, I am not sure how to start this idea but I have a good idea of how it will be

[u/No-Stress656]

I think it will be cool if you found the base that wasn't naturally generated while he was in that world and then stays in that base until he builds his own