I barely went a gym at all before crossfit - it was boring, and I didn't know what to do. At the recommendation of some friends, I tried Freestyle Crossfit since it was on the way to work and had convenient times. I could barely do a pushup! A little while later, and I can at least make a solid showing at things I would have never even considered before. Jake, Cody, and the rest of the staff are encouraging and even make total beginners feel comfortable doing their best while making sure we're not going to hurt ourselves doing something wrong.
If you're considering a workout you should drop in for a session - but give it at least a few times before you decide it's not for you. The demo WOD is rough if you're not already active!