First, take it slow. No, really. There’s no hurry, it’s not a competition, and you’re not 20 anymore (even though you look like it). Going too hard, too fast, is why a lot of people who would like to enjoy all the benefits of training, no longer practice the martial arts (or any number of activities). Go too fast, get injured; get injured, quit training.
Second, make sure they know who’s the boss (you!). You only do what your body says you can do. If and when a class moves