Do you know anyone at all who is a veteran to that gym or any other gym to show you the ropes? Eventhough the machines are sort of self explanatory you need someone to show you around. I've seen people at the gym sit the wrong way on a machine and they could've totally wrenched their backs out, not a good thing...
The person who signed you up could he/she now show you around a bit... Also if you know the name of the machine you could google it. Another suggestion is to use the free weights they are better than machines IMHO...
Keep uus posted on your progress