I really like going to the classes. Not sure if your gym has them or not, but I find the time goes fast and I like the variety.
If Im going to do the machines, I move around a lot. 30 min on the treadmill, 30 on the elliptical, 30 or whatever I have left in me on the bike. If you want to lift, I would check out the stronglift 5x5 program. Its free and there is even an app for that. Tells you what to lift, when, and how much weight. I would also advise to stay away from the weight machines, and go with the free weights.

I think the best thing you can do when you are in the gym is train with weights. Specifically doing compound movements. If you need a starting out program or want more information then send me a message.

Cheers!