the #1 most important thing to focus on when weightlifting is technique. You have to know which muscle you're working and focus on it throughout the entire movement. Even in a regular gym I'd say <5% of people know how to do things correctly. Lots of broscientists and one rep maxxers that don't care about anything except moving the weight.
Crossfit is really just terrible because you get a bunch of noobs doing something that makes them feel cool, but they have no clue what they're doing. If your plan is to move heavy weight very quickly....you're going to hurt yourself. If you're weak you'll hurt yourself early on, if you're strong it might be a couple years, but it's going to happen. Momentum should NEVER be used to move weight, yet in every popular crossfit exercise that's what they're doing.