Julieanne Kost of Adobe is the best Lightroom and Photoshop instructor I know. She’s just updated her free 33-page Lightroom Classic Tips, Shortcuts, and Quick Reference guide. It’s a concise PDF so it’s easy to search.
If you use Lightroom Classic this is a great resource. It’s amazing all that Lightroom can do. I don’t think any other photography software is better documented than Adobe Lightroom.