My first game

This is my first post, and my first finished game here on Chess.com. I recently picked up chess (a couple of weeks ago), but I have never played before other than against friends and family. I would like some tips on what I can improve, I know there is a lot. I have another game to show as well (a better gae), but I'll post that later.

What I mostly want pointers on is my opening. I have some general "ideas", but I don't always know how to prioritize these ideas. Mostly, they are:

• Control the center
• Move every piece once
• Develop all the pieces into the game
• Prevent the opponent from doing the same thing
• "knight before bishops"

Now what I've learned is not to follow fixed openings and moves, you have to be dynamic. So that's why I want to get some analysis on this particular game and situation. Moves that would be better etc.

I also would like some pointers and tips on tactics and positioning. I tend to play in the moment, without a plan for the "future". I am very materialistic. I might think 4-5 steps ahead, analyze his possible moves and mine.

Now in the endgame of the next game I will show you, I thought I did very well on the latter mentioned tactics. But first, here is the initial game: 

Thanks for all the comments and tips so far. 

"When you're superior materially, the better tactic is to exchange pieces whenever possible (this simplifies the position)"

That is one key tactic within chess. I became more aware of that in a latter game where I was up 3-4 points, and I just traded in all the pieces and was left with a bigger percentage even though we "evened out". I did not want to trade in one of my rooks at first because I was afraid of a rook and bishop end game, although I might have gotten a quicker promotion?

"4 dxc3 seems more accurate."

Could you elaborate this for me? Is it to open up for the queen?
Basically when I did this move, I had in mind; "take towards the center". I heard that in a training session on Chessmaster, from Josh Waitzkin. Might be one of those moments when you follow the dynamics and not the rules, huh?

14.Ne5 was a better move for white, threatening Q and B, worst case trade N for N

17.Black had a better move Ne2, trades N for R in move 18.

28.Black had better, Kf8

30.RxBf7 for black was better, and this is where I stopped counting his mistakes.

This was basically a game where the winner made less mistakes. But you still made some. 

You asked about the opening, so I'll only focus there on your first ten moves.

1.e4 e5 2.Nf3 Nf6 - This is called the Petroff Defense.

2. Nc3 - The typical way handle it is Nxe5, but your way is also fine. Like you said, knowing principles is much more important than knowing variations.

5.bxc3 - You have doubled pawns, but he's given up the bishop pair. It's a fair trade that leaves each side with plusses and minusses.

9.Rb1?! - This is the first move I really disagree with. The bishop on g4 is tying down both your knight and your queen. I think an immediate h3 is called for, putting the question to the bishop. 

10.Bb5?! - Again, h3 would have been a better choice. Perhaps your opponent did not exploit this weakness, but better opponents will.

...

I fast-forwarded through your game to see whether your opponent had a chance to exploit this strategic mistake, and he did but he missed it!

After 12.cxd4 Bxf3! 13.Qxf3 Nxd4! 14.Bxd7 Nxf3+ 15.gxf3 Nxd7

You're down a pawn, you have 3 isolated pawns, you have doubled pawns, you've lost the bishop pair, your kingside pawn shelter is destroyed, and you're already in an endgame. At least you have bishop vs knight, but I doubt that's enough to save this position.

Thank you all for your help, I learned alot.

Likesforests, I see what you mean. Though was "keep rooks on open files", but I see that this is in no way an excuse to ignore the knights pin to the queen.

I have another game too that I would like to show. Seeing how much I can learn from analysis like this, I would appreciate some advise on this as well.

I think I might have broken more of the basic principles in this game, but it also allows for some interesting development. Although I feel that a common denominator for these wins are the slightly weaker opponents.

My ranking was 1200 and it was one of the first games I started here on Chess.com. I played black:

2.c5?? Gives you nothing, risks the queen, even gives white a chance to mate.

19.What do you want with d5? He's doing you a favor by opening the f file! 

How does it risk the Queen? White a chance to mate Huh. please explain your thoughts. I don't see nothing blunderious about 2...c5?? It a move fighting for control of center from the flank, it doesn't block development of your pieces. One more thing, Is blunderious a word?

CheeckMatee, White doesn't get a strong queen attack in most lines:

   3...e6 4.Bb5+ Bd7 and White can't play Qxd5.

   3...Qa5+ 4.Bd2 Qxc5 and White can't play Bb5+.

   3...Nc6 4.Bb5 and Bd7's not necessary, but Black might play it by accident.

   3...Nf6 4.Bb5+ Bd7 and White can't play Qxd5 

So we can't tell him c5 is a bad idea because it leads to a queen attack. But we can warn him that if he uses his queen to protect d5, then don't play Bd7, because that would hang his pawn and maybe give his opponent an attack.

on move 12 what's wrong with gxf3, i don't see how to exploit the weaken K position.

 c5 is perfectly good and is even a theory line.

You are right, that's probably the best move, and I don't see an immedaite way to exploit the weakened king position. Which makes another point--there are often two ways to avoid a disaster: good strategy, and good tactics. Strong players have both skills.  :)

 What do you mean white can't play Qxd5? I don't see what  would stop him.

 Qxc5? There's no piece on c5?

If he plays Qxd5 in either of the lines where I said he can't, he immediately loses his queen, and at most levels that means losing the game.

1. e3 d5 2. d4 c5 3. dxc5 e6 4. Qxd5 Qxd5 and Black wins.

1. e3 d5 2. d4 c5 3. dxc5 Nf6 4. Bb5+ Bd7 5. Qxd5 Nxd5 and Black wins.