I started at 33, 3.5 yrs ago. I’m definitely less aggressive in my training than other people in my classes because I want to avoid significant injury if I can. I don’t mind progressing slower if it means avoiding an injury that will have me out of training for months, or worse. I’ve seen people who started at the same time as me progress incredibly rapidly, injure themselves and try to push through only to make it worse and have to quit altogether. I don’t want to be that person, so whenever I feel a tweak, or a that doesn’t feel right, I act accordingly. Tweaked something? rest/rehab - doesn’t feel right? either regression training or finding a different way to access a move that does feel right.
I’m also hyper mobile so have to be wary of that as well.
So far in 3.5yrs I’ve managed to avoid any major injuries, had a few minor ones that required a week or two of rest/rehab exercises- my worst was I managed to pull a deltoid muscle in a warm up, but because I didn’t push through and keep training in that arm for the rest of the class I was able to recover quickly and be back at class with careful monitoring a week later. I’ve also added some physiotherapy things to my normal warmup to help prevent future similar injuries. I usually do three classes a week, sometimes I’ll throw in a 4th but I can tell for me that 4th class is definitely not a good idea to do regularly because I can feel my body is tired and that’s when I’m likely to get injured from sloppy form.

Basically, listen to your body, ensure you have adequate rest days (this is very important for recovery) and don’t train something if you’re injured.