Where to start
Just come and stand quietly
You do not need to know the whole order of Orthodox worship before your first visit. Come to a service, stand where you feel comfortable and observe respectfully.
If you want to light a candle, submit a prayer note, ask about confession or simply understand where to stand, ask after the service or speak to the candle desk.
If you are thinking about confession or Communion, speak with a priest. This is better than trying to solve everything from random advice online.