Where do I start?

nomorewishing

So, I'm new to the whole exercising thing. I've been trying to lose weight for as long as I can remember, but other than walking and zumba on the Wii, I have absolutely no idea what to do. The gym is out because I'm unemployed and I have a really bad back, so I'm scared of just doing random things and hurting myself. I just don't know where to start! Any suggestions?