Okay, but what do you do if your opponent plays 2.cxd5 instead of 2.d3?
Why not black's d5..to d4first???

First, the title made you wonder.
Second, the best offense is a great defense!
Black Queen's pawn forward (d5) then forward again (d4) on the next move , of course.
sorry for not stating clearly.
also, every opening has to have contingencies for moves you are not prepared for.

Okay, but what do you do if your opponent plays 2.cxd5 instead of 2.d3?
This is where a contingency plan is played...d8 to d5. the black queen
is out in the open but, it 'shocks' them that it's out there, alone. Though most players then usually play nc3 or straight
I've played many games and had to have varied contingency plans. The one game I used here was a model for a black opening that I
find good. I hope this helps.

After 1.c4 d5, white is going to capture with cxd almost every time.
In those rare instances when he doesn't, he's going to push d4 and then you're just back into the black side of a Queen's Gambit.
In those EXTREMELY rare instances when he doesn't do EITHER, he's going to play e3 to keep you from pushing forward with ...d4.
This defense is...um...interesting to look at, I suppose, but has zero practical value, since it exists only in fantasyland.
Fantasyland? then i'm peter pan dude!
if cxd then qd5. and you dont keep going to d3 with the pawn, stay there and defend.
read my input to quasimorphy above. relax and play chess...in fantasyland.
Qxd5 is not much of a shocker. That's the only move that immediately regains material. Unfortunately, Qxd5 should be met by Nc3, which forces you to waste a tempo moving your queen out of harm's way. Nc3 is white's "move again for free" card, and their position is simply better after Nc3. If your opponent is half decent there likely aren't many good squares to develop your queen to. If you keep your queen in the center, he can develop pawns or other minor pieces to force you to move it again. If you retreat, you lose control of the center. The problem with having your queen "out there, alone" is that players with a decent grasp of chess principles will chase it around the board and force you to essentially waste moves, while they develop more pieces, gain more spatial advantage and center control, and get ready to castle or set up an attack.
What move would you make after Nc3?
the fact it took you 7 moves to develop a piece other than your pawns is, to say the least, troubling. you also have almost no control over the white squares, which only gets worse when you trade away your white bishop for a knight. it might work at your level but i wouldn't get too attached to it.

Okay, but what do you do if your opponent plays 2.cxd5 instead of 2.d3?
This is where a contingency plan is played...d8 to d5. the black queen
is out in the open but, it 'shocks' them that it's out there, alone. Though most players then usually play nc3 or straight
I've played many games and had to have varied contingency plans. The one game I used here was a model for a black opening that I
find good. I hope this helps.
I should hope players of the white DO consider Nc3 straight away, since afterward, they are not only multiple tempos ahead in development, but have a central pawn majority to boot. Black is already well behind by move 3. This is no way to begin a chess game.
it works...well enough

Qxd5 is not much of a shocker. That's the only move that immediately regains material. Unfortunately, Qxd5 should be met by Nc3, which forces you to waste a tempo moving your queen out of harm's way. Nc3 is white's "move again for free" card, and their position is simply better after Nc3. If your opponent is half decent there likely aren't many good squares to develop your queen to. If you keep your queen in the center, he can develop pawns or other minor pieces to force you to move it again. If you retreat, you lose control of the center. The problem with having your queen "out there, alone" is that players with a decent grasp of chess principles will chase it around the board and force you to essentially waste moves, while they develop more pieces, gain more spatial advantage and center control, and get ready to castle or set up an attack.
What move would you make after Nc3?
if he began w/ c4:
.....move qd8. that move nc3 is normal but then to contingency plan B.
e5 which opens up my bishops.....depends on his move after my qd8?
I love this kind of talking and analyzing...thank you
Play Chess!!!!!!!!!!!!!!!!!
I use this opening alot, alot and 86% it works(at home or online)
'ArrowHead' defense, I call it. plus 'The best offense is a great defense!' I have practiced and know the in's and out's of this opening and I like it. Tell me now, what is wrong with black queen's pawn opening then forward again? Tell me what is wrong or not????