I think a lot of people feel like this when they first join. Most gyms do an induction either one to one or with a group and show you round everything. If you haven't already book in to have a tour of the facilities before you become a member, have a word with the person who takes you round and let them know this is the way you feel, they might be able to suggest things/reassure you. I've worked in a few gyms and they can be very different in atmosphere to each other so check out if it will suit you.
When you first start, if you are able to go and work out at the same time each time, not only does it help you to form a habit, but other people do it too so you start to see the same people and recognise faces and can chit chat to people.