I have talked with every NPC I was presented, including non main ones and every location. And couldn't do anything new. And yes, I did watch the tutorial, but not everything happened as in the tutorial. That may also be an issue on my end, but it's a first among the Ren'py games i have played.
I forgot how Ren'py works. But if you could, id recommend having some variables in which you store data. Data which allows you to modify in the future instead of hardcoding everything. I think Ren'py has a flag approach.
Im a new at coding, so I could be wrong.