The most common beginner mistakes: moving the edge pawns, moving the same piece twice, bringing the queen out early and forgetting to castle.
In this position a move like a4 or h4 does nothing. Develop a piece or strengthen the centre instead.
One more mistake: leaving pieces unprotected. Black attacked the queen with a knight but left the e5 pawn unprotected. Move the queen away and take the pawn with check.