Its important to be clear about the type of game you want to make versus what’s doable etc.
But its also not really necessary to start simple if you’ll just end-up getting bored and may quit.
So do a self-realization check now, to ensure you have the level of commitment that’s needed.
Example: if you commit 2-5 years to this exclusively outside of work etc then you will progress.
Just be aware that anything with networking or multiplayer or super-advanced AI is a big ask!
Along with run-time changes to terrain, infinitely large worlds, or your own personal MMO etc.