Hi, I am a Reti layer as white and I play the benoni as black against d4 because I like open, aggressive and tactical positions. I find myself to struggle as black against e4. what openings do you recommend I try out?, I played the french defense for a while but I often have difficulties with the positions that arise from it and the king-side attacks that white gets from it.

There is no such defense against 1.e4 that is aggressive and sound.

Relatively speaking, the most aggressive defenses to 1.e4 are the Sicilian and French, and both see White get a major attack. Black's idea is to fend off the attack with a favorable ending.

The Caro and 1...e5 are slower, and is more likely to lead to a draw.

"I like open, aggressive and tactical positions"
++ Ruy Lopez Marshall Attack 1 e4 e5 2 Nf3 Nc6 3 Bb5 a6 4 Ba4 Nf6 5 O-O Be7 6 Re1 b5 7 Bb3 O-O 8 c3 d5, or Open Ruy Lopez 5...Nxe4

Sorry but I'm going to have to take issue with your use of the word sound.

The Sicilian, French and even Alekhine are all considered sound.

The Latvian and Elephant Gambit would generally be considered unsound, used for surprise and hoping the opponent doesn't know the correct response.

I suggest "rock solid" as a replacement term to get across your point.

I think that the CARO kann is a great opening for positional players like me creating consistent counterplay in the center to keep a good position always occupying the center. For aggressive players that like attacks I suggest the French which I used to beat my dad for the first time which occupies the center and creates consistent tension against the e4 square with most players collapsing under the pressure. For defensive players I think that the Pirc is good which creates a good center and a good pawn structure which doesn't launch a immediate attack but slow counterplay. And for beginners and Scandinavian is quite good which teaches principles of development and isn't as hard to memorize. Finally for advanced player the Sicilian is the best which can lead to variations like the Dragon which can dive into counterplay for both sides leading a positional struggle that can flame out into theory and tactics any time.

Though other openings like alekhine's and the Benoni are also very good with the Benoni being a very good opening which creates struggles and can be dominated by both sides if they find the elite tactics and theory that lay in the Benoni. Alekhine's is a uncommon opening that is underrated immediately developing a Knight and instantly attacking the center.

Best aggressive opening against e4

The latvian gambit , no doubt

Accelerated Dragon combines well with both the Reti and the Benoni. You can transpose to the Accelerated Dragon from both lines. It's also sharper / more tactical than the regular dragon. But it's in a similar spirit to the Benoni which you already play (although it tends to win alot more than the Benoni).

Another option, probably even better, is to start out with a french, but transpose into a french sicilian. They can play the Franco-Benoni but you already play a Benoni. This allows you to avoid almost all the anti-sicilians, which is quite huge. Then play the four knights sicilian, one of the more assertive sicilians for black. i.e.