Good point. Controlling the chute is half the fun, and it's also the longer half of the jump. Solo freefall is the way to go, but I wouldn't recommend it for someone who isn't sure they can take the first step on their own.As I said, my first (only) jump was a solo freefall and I highly recommend it. It is more expensive though. And tandem misses the other half!
This sounds a lot like what I did on my first solo jump. The instructors called it "the hill". It's the change in velocity after exiting the aircraft. I tried to put my front side to the ground because that was the way I wanted to go. I was actually moving forward so I had no control over my dive and coupled with the uneasy falling sensation from acceleration I forgot my posture and ended up on my back. I fell down the hill. It was easy to correct after the first few seconds when I was moving downward fast enough.*You're supposed to jump straight back and arch, but I jumped back and leaned forward like an actual inward dive, which meant I went tumbling out of the plane. I stabilized after a few seconds though.