This can depend greatly on where you go. Buddhism is in some important ways more diverse than Christianity. For example Tibetan Buddhism and Zen Buddhism, while they both grow from the same central Buddhist tenants (e.g., the Four Noble Truths), have very different approaches and trappings.
Additionally some places are going to be more formal and rigid in their approach than others. Some monasteries may be a bit more formal, whereas there are sangha groups that have almost a book club feel.
The best advice I think is to do as much research as you can about the place you're going in advance, and when you go there just do your best to be respectful. There may be written or verbal instructions for some things, and for others you may just have to try to be observant.
One little thing I've noticed is unless it's a less formal sangha meeting at a public space shoes will almost always be off. Many sanghas, centers, and monasteries are pitch-in efforts by members. If you notice other people helping clean up after a class or meditation you don't necessarily have to do it the first time, but make a mental note to give yourself more time in the future to stay afterward and help the next.
Finally, Buddhism doesn't permit teachers to charge for their teachings. However, maintaining a monastery or center does cost money. There will be a donation box/plate/something somewhere and you should really consider chipping in a bit when you can.
Hope this helps.