If you're style is defensive,
d4 would be nice, it avoids Sicilian which can be very aggressive with opposite castling and most lines are passive with not much attacking potential.
If you are playing queen's gambit, beware of Albin countergambit as the game can be highly aggressive.
If you're opponent plays (Old)Benoni Defence, I recommend
1. d4 c5 2. d5 Nf6 3. c4
1. d4 c5 2. d5 Nf6 3. c4 e5 will be a very passive game
1. d4 c5 2. d5 Nf6 3. c4 e6 might be slightly aggressive on the queenside, but you could should be able to prevent any potential successful attacks
As for Benko gambit, I recommend
1. d4 c5 2. d5 Nf6 3. c4 b5 4. cxb5 a6 5: b6/e3
b6, the queen would take and white will attempt a queenside attack
e3, you will be the one attacking, however, it should be easy as white's position is quite locked up by the pawns
Now if you're opponent plays dutch, it is defiantly an attacking game. Dutch is normally rare as it does nothing for black development, it only starts an early kingside pawnstorm but weakens their kingside, so you'll just have to defend the kingside or attack with your opponent.
I'll also recommend you to learn the London system which is a highly passive game and normally is a draw. If a draw is fine for you, you would want to look up the London system.
P. S. If you send some of your games, we could find openings that suit your style