This app was mentioned in 3 comments, with an average of 1.33 upvotes
Check out Stephan K's app - it explains the basic positions and their progression. https://play.google.com/store/apps/details?id=com.grapplearts.bjjroadmap
That's to help with the overwhelmedness from a "what's going on" perspective.
Try this:
https://play.google.com/store/apps/details?id=com.grapplearts.bjjroadmap
Apart from this, and perhaps Gracie University, i don't know of any other guides.
Never read both fyis but Kesting is reputable and Rener Gracie materials are okay.
The BJJ Roadmap from Stephan Kesting was a game changer for me. There are also many other tutorials made by him.