Hey prism, when I first went started going to the gym, I would stick to those machines they had, because I felt weak, and was afraid to do any real exercises like bench press, squats, etc. I thought people would look at me and make judgements on how puny I was. Then I realized that I don't care what they think. I went into the gym with the attitude that I had goals I wanted to attain, and no one was going to stop me from getting there. I started benching a ridiculously low amount because I had no muscle, but thats not what mattered. I figured that the other people in the gym could think what they want, but I just pictured the day when I showed up at the gym an was benching more than them, and all they could do is stand there in awe. Hasn't happened yet, but I'm on my way.
However, I have found that when you go to the gym, if you respect others, they will respect you, and realized that everyone is there for their own reasons. Whether you are bulking up or slimming down, everyone is going somewhere. You may even find that the people want to help you reach your goals.
Good Luck!