for health and safety reasons they are required to give you and induction if you ask for one whether you are a full member or just a guest. This can be as basic as just showing you how to use the machine, some gyms will offer to do you a training programme free of charge, but at the gym I work at this would only be offered to members as we get so many guests to do it for them would be an impossible task- but they HAVE to show you how to use the machines so don't worry about that.
You should go about 3 times a week to see results, so wouldn't it be cheaper to become a member? I guess it depends on guest fee prices at that gym, but I know at ours just paying to be a guest twice is more than a full months unlimited membership.
you have to get yourself some trainers and some kind of jogging pants, again for H&S reasons you can't just wear normal flat shoes or jeans or whatever.
hope this helps
do you have a Cannons gym in your town? it's the best