Which pawn should i take it with (or any improvements i can make to this opening)?

I need some help analyzing this position from this game that I lost recently. If this position occurs, which pawn should i take the light-squared bishop on c6 with? The d pawn or b pawn? If there is any improvements that i can make the opening, please let me know. The link for my game is down below:

https://www.chess.com/game/live/28053035033

I accept any further comments about my performance in the game so far, since these days I have been aiming to get past 1200 rating in rapid. So far I am trying to improve more on my tactics and learn more about the opening and especially the endgame by analyzing the games I lost. 

I am still only learning too but for what its worth; I would take with the b pawn.

My reason would be that the d pawn is more important as it is on a middle file.  

Interested to hear thoughts from better players.

I see. And it is a mate threat right, if I am not wrong? But what if white doesn't play Nxe5 after takes?

Thanks bro

dxc6
opens diagonal for Bc8
opens file for Qd8

after bxc6 Nxe5 black is in trouble

It's a Spanish Four Knights Game (1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Bb5 Bc5) and after 5. Bxc6 dxc6 6. Nxe5 the most accurate reply is probably 6. ... Bxf2+

The line you gave doesn't win a piece because of 7. Nd3.

7. Nd3

I also know what you're doing... you're blundering.

You'll develop them with either Nxc5 or with Qe2 or 0-0.

White is a Pawn up and Black has very little to show for it.

You are 2600 in BLITZ, and the advice you offer is the sort of cheap trick that only works in Blitz.

Your first mistake is move 4, allowing a favorable version of the Fork Trick.

I see that you intended to play the Berlin (3.Bb5 Nf6), which in these lines, you usually take with the d-pawn to open up the Bishops.

HOWEVER - 4.Nc3 is an option for White and you are now in the Spanish Four Knights, which usually arises from 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 (Same position as your game).

Black has two equally viable options, and both require a lot of studying, because if you know them, Black has little to no problems, but if you do not, this is not the type of opening that is playable on principles alone.

Which of the two opens is better depends on your style of play.

For the more positional player who prefers king safety and a calmer game, 4...Bb4 is the answer.  Do make sure you pick up a book though.  Black cannot mimic past move 6 as 7...Bg4 without taking the knight on c3 is a mistake (5.O-O O-O 6.d3 d6 7.Bg5 Bg4?)

For the more adventurous player that is not afraid to sacrifice a pawn with massive complications and an attack with Black, Rubinstein's pawn sacrifice with 4...Nd4 is the way to go.  But you better know the theory or you will lose quick.

There is this weird idea of 4...Bd6 that has had some recent hype, but it usually will not make sense to the average amateur below the IM level.  I highly suggest one of the first two.

While 20+ years old, the four Knights theory has not changed much in the two main lines, and I suggest getting the old book from Everyman with the Blue Cover (Not sure who wrote it - Jan Pinski maybe?).  Most other Four Knights books are White-Biased and only give a repertoire for White.  This book is objective and also gives the Scotch Four Knights (4.d4) and Glek (4.g3), which you will need to know anyway as a 1...e5 player.

White can play 8.Qe2! instead of 8.Nxe4?

And if 8...Bf5 or 8...f5, then 9.Nxc5 and 10.f3

Follow my advice in post 13 and invest the 20 bucks.

I'd take it with the d pawn. It speeds up your development by opening the bishop's diagonal. However, I think both are ok

Yeah, they should go back with the knight defending the f2 pawn

I was right for once! Yay!

If you know how to install Stockfish or Leela, you can get free advice from 3600+ rated players.

Both Stockfish and Leela says, dxc6.

dxc is a common way to capture in the Ruy and Scotch... sometimes this confuses some new players who are taught to "capture towards the center" with their pawns.

The Qd4 tactic is a common one is various 1.e4 e5 openings.

In other words this stuff is worth remembering.

In my humble opinion, you should not move  rook to e1.