Note that the Mac App Store version has restrictions compared to the direct download version (e.g., no raw import for some formats, less filesystem access).

If you tell me what you are looking to do, I can provide a more tailored guide: or renaming files? Editing (unskewing, editing EXIF data, resizing)? Browsing and organizing images? Videos - Lemke Software

Lemke Software's YouTube channel features video tutorials for specific functions.

The Lemke Software GmbH Forum is a good place to ask specific questions about version 11.8.