Im a little nervous because I'm going to be starting a martial arts class (taekwondo) and I don't know what classes are like. Has someone been to one of these classes and can you give me a basic idea of what its like?

Well, they can vary quite a bit from class to class. As your first time, I don't think you will be subjected to any beatings, if that is what you are nervous about. Heheh

We would usually do some meditation and warm up to start... then some basic practices/training... then either some sort of group practice/drill/etc or branching off into smaller groups or individually to practice more specifically on what you're focusing on

Piece of cake! You learn basic moves first. Teachers are patient and realize they have all levels of athletic ability in the class.

So much can differ depending on the master and even the school

Normally there will be some exercise and then you will work hard on forms, Normally different belts in same class you will work on your items up to a point and then watch others.

It is good exercise, I am well over 50 and still do some ( different forms)

There's no need to worry. Taekwondo has a culture of respect, and you should be treated with respect——and made to work hard. Enjoy your training!