A few simple habits will help you feel comfortable at your first hosted tea gathering.
Arrive at the agreed time, follow the host’s instructions about shoes and seating, and ask before taking photographs. Tell the host if sitting on the floor is difficult for you.
Follow the host’s cues
Watch how other guests receive the bowl and follow the instructions for that gathering. Practices can vary by school and setting. It is fine to ask a short question when you are unsure.

Choose the experience you want
A formal tea gathering and a craft workshop with matcha offer different experiences. Check the description when booking so you know what the session includes.
Further reading from the Japan Tourism Agency
Explore teaware painting and matcha at Edo Saryo · More Shibuya travel guides