Hi @Happleandhorange
I'm actually a resting LM BodyCombat instructor and happy to answer questions if that can help.
Probably just find one class that you like and do two or three sessions a week, depending on how you feel. Then once you feel established with one thing, maybe do a second class type to add variety and maintain interest. I mean I just did BodyCombat for 18 months there, it's the only class at my gym that I was interested in. But in days gone by I would do Barre (sadly gone, now integrated into Shapes) and Core as well as BC.
I suggest talking to one of the instructors, and see what they would suggest. They are really great at getting people onboard and they want you to find something that will make you decide to commit to the gym and become a member. Maybe they will suggest trying BodyBalance, Core, Shapes, which are Pilates/Yoga like workouts.
Later on or if you want to try something a bit more hectic, then you've got BodyJam, BodyCombat and BodyAttack. They're all a similar intensity, but dance, martial-arts, general aerobics respectively.
One last remark. You'll find in those classes, that some people are ludicrously fit and energetic and bendy. Don't worry about them, let them do them, just you do you. If you keep turning up, you'll notice big improvements very quickly and that's what it's all about.
Good luck and please keep us posted!