Have you had her fork open at all? Every so often forks are shipped with tokens unknown to the user.
A kicking off point for air pressure in forks (I was once reasonably reliably informed) is to take a persons weight in kg, and use that as the PSI setting, so a 140lb person at 63.5kg would give a fork pressure of 63.5psi. I’ve generally used this as a starting point myself, but for me personally I find this too harsh to my liking and I end up around 10psi lower than if I used this method.
Adjusting sag will get you to bottom out, but this also chews up some of your available travel, and may also mean that the fork sits in the bottom of it’s travel, rather than the middle or towards the upper end (always nose down). Most forks should have 20-25% sag. This conundrum is solved using tokens - decrease the air volume, increase the progression, lower the air pressure…
I haven’t watched this, it was just the first hit on Tellytubby:
The 200-hour service can be done by the home mechanic with the correct tools and some knowhow, so I think this is achievable for you. The tuning the shim stack is a bit more specialised and if not done correctly, say goodbye to the damper!
For 200-hour service, there are enough videos on Tellytubby from GMBN, MBR, Sram, Fox, etc that go into this. Correct tools is generally what holds people back.