Some Getting Started info, as well as other resources for Dreamers, are in the Dreams Quick Reference: https://www.reddit.com/r/PS4Dreams/comments/bede59/quick_reference_guide
Before you get too immersed in the CoMmunity's roots, Here are a few buzzwords that are important to know.
Here is the dedicated tutorial page
Videos[]
Dreams Gameplay - How Do You Actually Make Stuff?