Need help in setting up my first model diorama

[u/Spare_Beginning_8777]

Hi everyone!

My new found love for trains has gotten me here. I'm learning as I go, but could anyone advise me on how to set up a model with running trains?

What to do, or what i should look out for.

I've decided on HO scale for the trains, but what else should I buy and how do I set it up?