Hi,
Usually if you first join a gym, a staff or personal trainer would go through a fitness assessment. At least run discuss with you on your needs and that personal trainer will set up a schedule for you.
If not ask for a qualified personal trainer there (every gym has one) for consultations. Just doing long steady cardios has results initially but will be less effective thereafter.
Workouts at the gym should be intensive and challenging(adjusted according to your fitness levels) for fat loss results.
Otherwise, here is a recommended product , compiled by a recognized fitness expert ,and author of several publications - Turbulence Training - this will show you how to lose body fat and build muscle at the same time.
The key here is getting the nutrition right and using short effective workouts.