Going to first session

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.

At a Theravada monastery:

• You have to be familiar with taking refuge in the Triple Gem and taking of the five precepts: http://refuge.sirimangalo.org/
• Remove shoes and hats when you enter the monastery.
• Wear conservative clothing. White color clothes are more appropreate.
• Avoid shouting, idle chatter and laughter(can smile when appropriate) while you are there
• Avoid running. Walk quietly.
• While listening to Dhamma talks or meditating with others, turn off your phone or keep it in silent mode. If you need to answer an urgent call or text, quietly go outside the room.
• If you make an offering to the Buddha or the Sangha, do it using both hands and bow afterwards.
• If you offer food, do it well before noon as monks cannot accept food after noon. Make sure the food is prepared for consumption as monks are not allowed to cook food.
• Do not offer food that is already consumed by another.
• When offering food to monks, don't place it on the table expecting them to take, like in restaurants. You must personally serve every curry into the bowl or plate. If they don't prefer a certain dish, they will indicate by covering the bowl with hand as you try to serve.
• Don't consume food while attending meditation sessions or listening to Dhamma talks.
• Don't smoke inside the monastery.
• If a monk is standing and addressing you, don't be seated. If a monk is seated on a couch/bench, do not sit on the same at the same time. Sit on the floor or sit on a chair which is lower and less luxurious. Do not sit directly facing a monk or a Buddha statue. Sit to the side. When sitting(chair), do not put one leg over the other or sit with your legs wide open or stretched infront.
• Do not address the monks by name. Use respectful terms like 'Bhante', "venerable sir" etc.
• Do not try to shake hands with the monks, pat on the back etc. Avoid all unnecessary physical contact within the monastery.
• Do not take selfies with Buddha statues or monks. Do not take pictures with your back turned to the Buddha statues.
• Do not try to practice your own method in the monastery. Follow the instructions by the teacher.
• If you wish to make a donation, don't hand money to the monks as they are not allowed to handle money. Instead, look for the donation box or ask them how to make a donation.