Just get started? Here are your top 6 getting started pro tips:
1) Gi Life. You didn't realize you signed up for laundry as a second hobby, but you did. Number one rule: wash your gi. Number two: don't dry it. Gi's tend to shrink considerably in the dryer, so hang dry it. When drying rash guards, exclude anything with velcro. The velcro will snag at the rash guard and damage the fabric. There are some expensive "active wear" detergents, but a basic detergent will work fine. Clorox 2 doesn't hurt. There is a weird mythos in BJJ about not washing your belt. Go ahead, wash the belt. When you receive a stripe, I recommend drying the belt before you wash it. It will help the tape stay on.
2) Beginners class is for everyone. The two major differences between the beginners class and the regular class are 1. you don't roll in beginners, and 2. you will cycle through positions a lot faster in beginners. There is so much to learn in BJJ, that people often learn some basics early on, and then don't revisit them. This leaves experienced grapplers with poor fundamentals.
3) Start with situational rounds. When you are just learning to roll, there is a lot happening. Sometimes, you don't even know what's happening. I recommend you start with specific situational rolling. For example, start in closed guard and just try to pass. You should feel comfortable asking someone to do this with you. Everyone is here to be a good training partner.
4) Take it easy. Jiu Jitsu is exhausting. Warm ups are exhausting. Sometimes cleaning the mats feels exhausting. Go at a pace that you feel comfortable with, and do not try to out work/out muscle your training partners. Even if you are successful, I promise that you aren't actually learning anything.
5) Tap often. You are going to get submitted in class. Every class, actually. Don't burn energy and risk your limbs for nothing. When you are in trouble, tap. Until you learn specific escapes and have spent considerable time drilling them at a slow pace, just tap.
6) Start watching Jiu Jitsu! Many people come to BJJ due to MMA, so they have never actually watched Jiu Jitsu. The best way to get a sense of the way Jiu Jitsu works is to watch it. At first you won't have any idea what is happening, but as time goes on it will start to make more sense. Keep at it. You will begin to learn and appreciate the support.