I will try to give a few ideas based on the limited information, and trying to follow some common sense regarding development and the moves your opponent played.
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1. e4 e6 2. d3 c5 3. Nf3 Nc6 4. g3 (4. Be2 g6 {4...d5!} 5. O-O Bg7 6. c3 Nge7 7. Be3 d6 8. d4) 4... g6 5. Bg2 Bg7 6. O-O Nge7 7. c3 d6 8. Re1 e5 9. a3 O-O 10. b4 a6 11. Be3 b6 12. Nbd2 h6 13. Rb1 Be6 14. Qc2 *
I am not a big fan of the King's Indian Attack. Frankly, your opponent's response, which I like a lot, with an early g6 tends to really blunt the main k-side attacking premise that makes this opening fun for white sometimes, and thus, the main reason to play it. The other thing is that in this c5 variation, black always can go for the normal Sicilian "equalizing" move, d5 with little trouble.
The fact is that your second move cedes space to black from a very early stage, so it is hard to believe that you will be able to gain an advantage out of the opening. You might want to hide your intentions a little more too with 2.Nf3, 3.g3, and only then, play d3 before showing your hand. He might not play a line with g6.
As to what to do, because g6 really makes it hard to attack his king as in the main lines, the line I gave sets you up to play the re1 to d1 and the ra1 to b1 and eventually to play bc. If he opens the b-file, you will try to play on it, and you are probably better placed to use it, or if he opens the d-file, you can play for d4. If you really do not have play on the k-side, you have to look at the center and q-side.