First you need to establish where the bike is now.
Was the back lowered? How? Stock spring?
Was the front lowered? How? Stock spring?
Condition of components?
You will need to compare to stock ride height. If needed, do whatever you need to get it there. Then measure sag. Then you can start turning the something on the yellow spring.
I suggest taking it to a competent dealer with a good reputation OR a suspension expert. The goal being to bring the bike as close as possible to stock = height front and back + some shock adjustment. Then ride.
is really good advice.