I took a volunteer training at a fire/ranger station in the mountains once. It was clear that the firefighters that worked there during the week used the WOD from the main cross-fit website for fitness. They had basic weight lifting equipment in the garage plus a weight room and they had the WOD with scores on a whiteboard. It looks that you could do cross-fit on your own if you have the equipment available. That might be one way to try it out, although it sounds like the whole social thing is probably 50% of the experience.
I have not ever done it myself. I feel I need a more linear structure and something with a clear path of progress toward strength. My experience with something more random didn't gain me much progress.
Female, 5'3", 49, Starting weight: 163lbs. Current weight: 135 (more or less).
Starting squat: 45lbs. Highest squat: 167.5 x 2. Current Deadlift: 210 x 3