Need exercise advice!

Ok so I am totally clueless! I've lost 34 pounds so far just with elliptical and eating better. Ok so now what do I do? I have a gym pass with basic cardio machines, free weights and the weight machine things. I have 71 more pounds to lose hopefully and am just looking for an appropriate routine to help me lose weight and also tighten up my body if that makes sense. Specifically the back of my thighs/bum.

Can anyone point me in a good direction? I see tons of stuff about lifting, but am honestly probably too intimidated, I go to the gym when all the high school kids are there and I can't change my gym time just looking for the best exercise. Thanks in advance for your help!!