You can do most of the WODs on your own. You don't need too much equipment.
This is what I do as I don't want to pay the high fee's for the local crossfit gyms. I have a bad back that I have to watch out for but I get most of my workouts from:
The WOD Shop - Online CrossFit Workout of the Day (WOD) Generator
I use mostly body weight and kettlebell workouts.