I only quadrilled because I had to. I was on the college team and did exhibitions, and also did a quadrille at USET. I HATED it, and so did Horsie. It was kinda fun in college-we were all on schoolies, and they knew what they were doing, but the 3rd L one was excruciating, mostly because we didn't have much practice time together, since we were from different barns. Our coach was a self-confessed freestyle/quadrille guru, but the choreography never quite jelled, and I remember Coach's frustrated red face most of all--
When someone shows you who they are, BELIEVE THEM.
The tests are on the USDF site. It is easier to have people in the barn. If you are all educated riders (who can watch each other and 'rate' the speed of their horses), it takes about once a week. If not, it takes more time and practice, to learn those skills. All you really need is a person who can watch the alignment, say turn 'now'/etc. If not, then get a coach. (A group I (both much larger and as a quadrille) won a lot in CA years ago. ) Its fun and great for the horses to learn to 'work well' with others. If they do not work in pairs (in all gaits), then (initially) work on that.