Seasoned gym users are feeling more optimistic round about now: the influx of this-year-I'll-do-it new members is abating. Soon the newbies will be mostly gone. Hopefully, that's not you.
(Apologies if you don't care for fitness-related posts. There's a technical reason I don't use topic tags.)
Anyhow, it's well known that gyms take on far more members in January than they can cope with, because some huge percentage (80 or more, I think) will only last a few weeks. So if you're making a new start, be one of the winning twenty percent. Back off from the intensity if it's too much, and concentrate on coordination and technique. That applies to running, lifting weights, or whatever. Smooth action and settling into the training habit will get you there.
I like this book, by someone who knows what he's talking about. (Gentle folk tend to be surprised if they actually look inside military fitness books. There's no macho talk, not from the genuine tough guys.)
As for me, my conditioning training is in my back-garden gym, so there's no overcrowding. Just a need for a tiny motivation and energy boost to get me out of the door and running in the cold and dark. Easy.