If you ask a question and it's been covered in one of these well-written guides, you might get rudely dismissed by a very frazzled Jules. You probably won't, but might.
Initial (important):
New machine beginner's guide
Old machine beginner's guide
Getting started
Extruder flowrate calibration
Extruder tension adjustment
The perfect first layer
Leveling an old machine
Helpful tips:
Pausing at a specific layer
Splicing filament as you print
Filament:
Filaments known to work on the M2
Dialing in pesky black PETG