One thing you're missing is one key idea behind the Sicilian: Black wants to exchange his less valuable flank pawn (the c5-pawn) for White's center pawn (the d4-pawn). That means as soon as White plays d4 you should respond ...cxd4, no hesitation or thought needed. That's true whether Black has played 2...Nc6, 2...d6, or 2...e6. Note that when you delayed capturing that way, White temporarily won a pawn via dxc5, which White should never have been able to do.
Scicilian Defense Help Needed

One thing you're missing is one key idea behind the Sicilian: Black wants to exchange his less valuable flank pawn (the c5-pawn) for White's center pawn (the d4-pawn). That means as soon as White plays d4 you should respond ...cxd4, no hesitation or thought needed. That's true whether Black has played 2...Nc6, 2...d6, or 2...e6. Note that when you delayed capturing that way, White temporarily won a pawn via dxc5, which White should never have been able to do.

One thing you're missing is one key idea behind the Sicilian: Black wants to exchange his less valuable flank pawn (the c5-pawn) for White's center pawn (the d4-pawn). That means as soon as White plays d4 you should respond ...cxd4, no hesitation or thought needed. That's true whether Black has played 2...Nc6, 2...d6, or 2...e6. Note that when you delayed capturing that way, White temporarily won a pawn via dxc5, which White should never have been able to do.

What is "they"? If White plays Qxd4 after ...cxd4, then White loses a tempo from retreating his queen. If White wanted to do that, he could have done that earlier via 1. e4 c5 2. d4?! cxd4 3. Qxd4?! Nc6, but that is a weak line, which is probably the main point of the Sicilian: to discourage White's d4 by threatening to force White to lose a tempo retreating his queen.
I don't completely understand either of your questions, but below is what one database says about your opening. Note that Black immediately got an advantage, and soon gets a 60% win rate!

"They" is whoever I'm playing, and ignore the question I forgot they moved d4 before Knight f7. So while that makes sense for the beginning ideas, controlling how white interacts in the center is definitely strong, the part I don't understand is if the main idea next is to increase pressure in the center or to use the space gained on the queenside and put pressure there. Maybe both of those ideas work

When you ask about the next main idea, at which move and in which position do you mean?
(Sorry for the delay: I thought somebody else would jump in to offer detailed advice by now.)
Main feature of Sicilian Defense is Black establishes a 2 vs. 1 pawn majority in the center ( White pawn at e4, Black pawns at d6 and e6)
I will analyze your game over several posts. 1.e4 c5 2.Bc4 let the transpositions begin. Best response is the one you played 2...e6. Now the White B at c4 is biting on granite instead of attacking f7. White can choose not to spend tempii getting his B out of the way of Black gaining the Minor Exchange. In other words, it is too early for White to play his B to c4. The first reason was referenced above concerning loss of tempii or losing the Minor Exchange.
I will post again later with more analysis.

I will analyze your game over several posts. 1.e4 c5 2.Bc4 let the transpositions begin. Best response is the one you played 2...e6. Now the White B at c4 is biting on granite instead of attacking f7. White can choose not to spend tempii getting his B out of the way of Black gaining the Minor Exchange. In other words, it is too early for White to play his B to c4. The first reason was referenced above concerning loss of tempii or losing the Minor Exchange.
I will post again later with more analysis.
The second reason that 2.Bc4 is premature is that it telegraphs to Black White's intentions or plan of attack too early. Black can adjust his defensive plans based on White's having tipped his hand, ...e6. 3.d4, and White is signaling more transpositional possibilities, more specifically having to do with the Smith-Morra Gambit. I will explain in my next post. With 3...Nf6 Black attacks White's undefended and not indirectly defended pawn at e4. if White defends the e4 pawn by playing 4.Nc3 he will fall into a center fork trick that gains a pawn for Black (4...Nxe4 5.Nxe4 d5!) White decides to advance the e4 pawn 4.e5 attacking Black's N on f6. Black seizes the opportunity to transpose into a variation of the Advanced variation of the French defense that favors Black by playing 4...d5. I will explain all of this tomorrow, I'm tired.

That bishop placement in the Sicilian eventually loses a tempo to either ...d5 or ...b5 (the latter preceded by ...a6). However, admittedly if Black doesn't play carefully for a while, that bishop can become very deadly very fast. Ever see the Fischer-Reshevsky game of 1958-1959?
http://www.chessgames.com/perl/chessgame?gid=1008376
Sqod makes a very good point. Actually there are several squares that are very dangerous tactical foxholes. In the Sicilian in general the thematic d5 square. The tactics available to White on the e6 square and the f5 square. The tactical sacrifice of the exchange on the c3 square for Black in the Sicilian Dragon variation. And finally the b2 square in the Najdorf Poisoned pawn variation. Poisoned pawn is ridddled with tactics. I memorized 400 variations of the poisoned pawn. Had to, one reliance on general principles and bam White would spring a tactical shot, or Black would unleash a tactical riposte. Even today, with the chess engines, the theoretical argument about the Black Q going pawn grabbing in the opening is still a draw.

Actually there are several squares that are very dangerous tactical foxholes.
Also the b5-square in the Najdorf Variation. I once bought a book on the Najdorf and it was full of lines with sacrifices by White on b5, either from Nxb5 or Bxb5. The funny thing was, that sacrifice was always either a blunder or a brilliant forced win for White, and that blunder-brilliancy status fluctuated at almost every move, which required endless memorization on my part. That memorization requirement is why I soon gave up on the Najdorf and never used that book again. I now know exactly what Fischer was talking about in later years when he said that he hated chess because it had become just a game of memorization.
Sqod wrote:
Also the b5-square in the Najdorf Variation.
____________________________________________
I'd almost forgotten those times with my buddies from the Orlando Chess Club. We would car pool and share a hotel room (4 or 5 guys to a room). That is how we saved money in those days. Most of us were students with no income.
I remember the tournament games where I sprang the b5 square trap on Black, Those were short rounds at the Chicago Open. Many hours before the next round. Off to get plenty of good food, some drinks, and check out the night life in the city.
Hello everyone, so I have been experimenting with newer openings lately that what I usually play. My main repertoire is the Scotch, Center Game, (White), and simply E5 or D5 as black (non-gambit) beginner openings that I understand relatively well. Recently I have decided to mix it up as black, and I have been working with Tigers Modern and the Sicilian, I understand they are very complex openings, but I really like the style of games that come out of them.
Lately though I have reached a point where I feel I understand the general opening principles of each in the basic sense, and I can usually hold my own in the beginning. However, I find once I get to the middle game I have trouble finding how to precede. The game above was a 5min game that I played and I felt like my position was very strong, but at around move 22 I felt that my position was starting to complicated and I spent far too long in the game (1-2 minuets) just on the next 5 moves. I understand that 5 minuet games are short, but my problems steam from just not being able to fully comprehend mine and my opponents weakness.
Can anyone give me some tips on the game above and just in general about what the middle game pros and cons where for each of us (I am playing as Black btw). I ended up running out of time at the end but I still feel like I had decent chances. How would you have broken through my defenses, and where was I most weak are also other questions I am interested in.
*Oh also just in case anyone was curious my next move was going to be Bishop C2 if I had the chance to play it