My first visit to an Orthodox church: what should I know?
In short: You don't need to do anything special for a first visit. Dress modestly, arrive a few minutes early, stand wherever you feel comfortable. No one will judge you. Observe, let the atmosphere carry you, and don't worry about the rest.
The Orthodox nuance
A few practical pointers that may help.
Dress: there is no strict code, but modest dress is expected. Covered shoulders, a decent skirt or trousers. Women may wear a headscarf, but it is not required. If you have a large backpack, leave it in the car if possible — not by rule, but for your own comfort in the space.
When to arrive: try to arrive 5 to 10 minutes early. The Liturgy does not start on the dot, but arriving early gives you time to find your bearings. If you arrive later, walk in, quietly find a spot, and don't worry — it happens to everyone.
Where to stand: in the Orthodox tradition, the Liturgy is celebrated mainly standing — many churches have no pews, or only seating along the sides. A first-time visitor is not required to stand the whole time; if you have a physical difficulty or feel tired, no one will raise an eyebrow if you sit down quietly.
What to do: observe. You are not obliged to sing, bow, or make the sign of the Cross. The people around you do it naturally — if you want to follow, you may; if you prefer to watch, that is equally fine.
Candles: in almost all churches, near the entrance, candles are available for purchase (often a box with the price indicated and a jar for coins). You can light one at a candle stand. This is not an obligation; it is a gesture of prayer.
Holy Communion: if you are not Orthodox or have not prepared (fasting, confession), do not come forward for Communion. This is not a rejection of you as a person — it is care for a sacrament that has a specific preparation. You may receive the antidoron (blessed bread distributed after the Liturgy) if the priest offers it.
At the end of the Liturgy: if you wish, you can speak to the priest. Most are glad to talk with someone new. You can simply say it is your first time and that you have questions. There is no such thing as a stupid question.