Many maker spaces have created simplified PDFs focusing solely on the "DXF Export" workflow. These are 10-15 page guides that teach you just enough to export a file for a Glowforge or K40 laser cutter. Search for "LibreCAD Laser PDF" on GitHub or Thingiverse.
Have you used a specific LibreCAD tutorial that changed the game for you? Let us know in the comments below! Librecad Tutorial Pdf