First rule of training, is don’t hurt yourself.
Second rule of training, is don’t hurt yourself.
Third rule of training is, don’t hurt yourself.
These rules apply to every sport, not just climbing.
Drink lots of Liquid, it helps protect your tendons.
Be courteous and pleasant to others so that they are courteous and pleasant to you, so that you can all profit from training.
If you do hurt yourself, even in a minor way, take 10 whole minutes to think about it, go have a coffee, and think about it, do not carry on in any way which might make the injury worse. Do not keep squeezing and testing the injury, you only make something worse by hurting it more.
Tidy up your mess before you leave. After you finish turn to the training area and bow just like in Martial Arts, now do two things, say thanks and goodbye, and check you didn’t leave anything!