I've been training in various martial arts for about a year now. My main focus has been boxing, but I've also done a bit of muy thai and TKD. I'd like to move on to some sort of grappling art (Preferably BJJ), but it'll be awhile before I can get the money together for classes. In the mean time, would it be a bad idea for me to train/roll with other untrained people? There's 3 or 4 (untrained) guys who have been getting together every Sunday at my gym for the past couple years and training with each other for fun. None of them have been in any competition or had any professional training. My main concern is learning one way (the wrong way), then having trouble learning a different way (correct way) when I actually take BJJ classes. So, would I be better off to not do anything at all without proper training, or would it not hurt to get a little practice in for fun?