Yes, you will put your car on the blocks and use the stepped measuring device. Measure at the bottom on the front upright. That is where I measure my droop. Going to a setting of 1 and 3 (from 2 and 2) is just a 1mm difference in the front and in the rear.
When I set front droop I use the screws to get them as close as possible. I get the side that doesn't have the adjusting cam exactly right and then use the cam to get the other side correct. I have probably got you really confused now!!