First things I learned were the basic positions, mount escapes, and side-mount defense. That didn't take more than a day or two I think, and then I was allowed to roll with everyone else. Seemed ok to me, although it might have been more stressful if I didn't already have a general idea of how to twist limbs in painful ways. The people I rolled with were real good about pointing out my mistakes and giving me advice and everything also, which is very important to anyone's progress I think.