PruaSlicer Key Settings for PLA Beginner ???  

Use the defaults.

The settings are there for subtle tweaks that a beginner will not need - until no longer a beginner.

Cheerio,

RE: PruaSlicer Key Settings for PLA Beginner ???

Also put the slicer software into beginner mode and only the green subset of settings are shown. That is why it has beginner/advanced/expert in the first place. 

RE:

Also: Buy filaments you find profiles for in PrusaSlicer and use default settings. If you run into problems with specific models get advice here in the forums (post the zipped project file), don't just change settings because somebody made a YouTube video. Slicing is a complicated thing not a simple model conversion, it needs some practice...

To answer your initial question: No key settings, for basic printing and not too complicated models, leave everything on default. (see @diem)

RE: PruaSlicer Key Settings for PLA Beginner ???

No one show them the amount of settings in Cura 🙂 

RE: PruaSlicer Key Settings for PLA Beginner ???

Pfft.  If Cura was a car, I would surely wreck just getting out of my driveway.

In PrusaSlicer, I double check bed and extruder temps against the filament manufacturers recommendations - maybe a tad bit higher, then call it a day and print, print, print.  Works for me.