You will need something a bit firmer than sand, unfortunately, sand likes to move, so I would recommend patio blocks under your uprights just to help hold everything in the proper place.
I built my own pool too, and it is a lot of work, however, not nearly as complicated as one would think - ground prep is key here, get it perfectly level either by using a water level - cheapest, or a transum.
WRT compacting, you can compact your sand, I would recommend it, using a rented gas plate compactor and water. Only you can decide whether or not you feel up to the job, but it is relatively easy from an instructional aspect, just pretty hard physically.