You don't have to talk much while orienteering, but you do have to interact with other people in order to get the map in the beginning.
This is what I usually say:
Once you have the map, you have to sign up by saying your own name in Lähtö (Start) unless you have an EMIT control card, in which case you just punch it and start the race, I think. Remember to go to Maali (Finish) when you have completed the route, so that the organizers don't think that you got lost in the forest.
Here is a great Youtube video about fhe ABCs of orienteering.
p.s. In case you end up absolutely alone in the forest, make noise to keep the bears away.
Hauskaa suunnistusta! - Have fun orienteering!