first session D&D with a new group is always a little weird because you're simultaneously trying to figure out how to roleplay your character, how they relate to the other characters in the party, what the mechanics let them do, but also suss out how the DM is running this game, how much player freedom you actually have, all while you're on lookout for whether the group has That One Guy who's gonna ruin the game...
solving the mystery or beating the villain is wayyyyy down the priority list