I have done exercise classes but never used the machines at the gym. I'm a bit nervous about trying this. Is it easy to get started, do you get any help with what you are trying to achieve?
I am the opposite to you, I always use the machines and never go to the classes! lol. If I were you, I would book a session with a trainer to show you the machines and to work out a plan for you.
Whenever you sign up to a gym you are required to attend an induction where they will spend an hour or so taking down your stats and showing you how to use all the machines correctly.
In terms of what kind of support you get after this would probably depend on the gym itself and what sort of package you pay for but you can always keep in touch with the gym instructors and ask for advice and tips.
Should also have said when you go for your induction they should set up some sort of plan that suits you. Depending on your level of fitness this is usually quite a basic starter with short times on each machine at the easier levels. You can then build this up to longer periods of time on harder levels when you feel you are ready for it.