How would you play this opening as black? I keep fumbling through my openings and would love to improve and learn from others.  How would you play this position as black?
r1bqkbnr/p1pp2pp/1p3p2/n3P3/2B1P3/1P3N2/P1P2PPP/RNBQK2R b KQkq - 0 1
Well, Black has some weaknesses, is a little behind in development, and is down a pawn. The position isn't great, but things aren't hopeless.
The first thing I'd do is play Nxc4. I assume the knight was placed on a5 to do just that. White gets some doubled isolated pawns and loses a potential attacker in the bishop. It seems like a no-brainer.
Next, I'd develop the bishops with Bb7 and probably Bc5.
We probably need to deal with the pawn on e5 before very long. It's hard to develop the g8 knight with that pawn there. While playing fxe5 is possible, I don't like inviting the White knight to e5. It may be better to play d6 instead to attack the pawn from the other side, depending on how the game goes.
Black also needs to decide where to castle - the middle is too open to leave the king there for long. Both sides have their pros and cons. The movement of the f-pawn has weakened the kingside and White will likely put their remaining bishop on b2 to attack the kingside, but the queenside has a half-open b-file and it wouldn't take much for the c4 pawn to go to c5 to try and crack Black's queenside. Overall, I'd probably pick the kingside. An opened f-file might even be good for the rook after castling.
Obviously, any plan may need to be adjusted based on how White plays.