I'm really afraid when my opponent moves c5 after I play 1. e4

I lost a lot of matches against people who likes to play Sicilian Defense. I didn't know how to play. I didn't find the keys of the position. There is a lot of lines and variants in the theory to study.

An idea could be to play the Alapin 1. e4, c5 2.c3 so I will avoid many variants that blacks can choose, but I think there isn't many possibilities for win.

So I'd like to play 2. Nf3...but then  blacks can play of many forms. I should study a lot of theory and this it ins't easy.

What do you think of?

Here, an example. The last game I played.

that started out as an awesome Smith-Morra Gambit!

I play a closed system with Nc3,f4 and Bb5--the 2 c3 line is quite good as is various 3 Bb5 lines. I think playing the main line with 2 Nf3 and 3 d4 is tricky unless you have lots of time to learn lines or have years of experience.

This is like the danish, but it isn't. Someone played this as white against me, but the problem is that white must play perfectly or else they'll lose. It avoids alot of theory, and you just need to know how to attack.

2. c3 (shuts down black's attempt to control the center). Nc6

3. d4 cxd4

4. cxd4 e6

Watch the game to see the rest.

I personally like the Morra-Smith Gambit

I need practice with the SMG.  I never seem to get far with it. 

A lot of people recommend the Morra Gambit, but I'm not a fan.  I've tried the Closed Sicilian; don't like it.  I used to think the Grand Prix attack was pretty decent, but it's out of vogue now; I guess black found some adequate counter-play.  I've not tried the Alapin much; seems like a reasonable try.  If you're hellbent on playing an anti-Sicilian system, I'd recommend the Bb5 variations -- called Rossolimo when played against 2...Nc6, and Moscow variation against 2...d6.

The original question, though, was what do *I* play against the Sicilian.  The answer: Open variations.  For as much time as people spend poking around with anti-Sicilian systems, they could make a lot of head-way learning the main lines, and they produce the best game for white.  There aren't THAT many main branches, and you don't have to play the sharpest bleeding-edge theoretical lines.  You get to attack, you get the initiative and space -- it's very much the kind of game most people want when they open e4.

Learn to play d4. Avoid the scilcian all together.

Start playing d4 just because of black's first move?

What about the whole lot of the Indian family, Benoni, Benko Gambit and Dutch?

If you stick with 1.e4, youll only hav to spend about a week or two learning just one new system - a system against the Sicilian - but switching to 1.d4...?

1.e4 ... c5

2.d4 ... xd4

3.Qxe4

 To play against the scilcian, he needs to learn positional play. Playing d4 for a while will afford him that. Course he needs solid mid game skills to make it count. I rarely follow any systems.

I see that as defeatist.  It's like resigning to 1... c5.

Well, if you want to get a little advantage from the opening, then play the sicilian. Of course you must know tons of theory :) You don't want to learn theory? Play Alapin. It gives you good results for how much effort you must put to learn it. Also, many players would spend an enormous effort learning Sicilian lines, and they neglect Alapin. Still, it is a quiet opening. In live games against somehow lower rated opponents (<1800), try Smith-Morra.

3... Nc6 is the obvious next move, where does the queen best go from there?  I have a problem in deciding and I don't necessarily agree with the "book" on the next move here.  I think this line is very easy for black to get equality.

I dunno, looks like it leads to a nice equal game for black.

Every time this topic comes up, someone always makes this "contribution".  It's not very helpful.  There's a lot of rich play under both e4 & d4; you don't need to abandon one because of one particular response.  (Though, to be honest, I did -- I quit d4 because the QGD Orthodox bored me out of my skull.)

Even aside from that, in this case, I don't think your assertion of "needing to learn positional skills" is very applicable, either.  Energetic play and attacking skills are what is needed to defeat the Sicilian, IMO -- slow maneuvering is a recipe for defeat.

I think there are PLENTY of chances to win. In most variations White gets a nice pawn center and easy development, and Black has to be extremely careful.

Currently I'm rated 1900-2000 ish over the board, aiming to be 2100 once, and I was looking at some statistics.

1. As Black playing the Sicilian, I do worse against 2.c3 than against any other move.

2. If in my database I select only games of 2100-2200 people playing other 2100-2200 people (the sort of level I'm aiming at long term), then 2.c3 is easily the best scoring Sicilian variation for White.

GM Tiviakov (2685) has a huge plus score as White after 2.c3. It only becomes drawish for him when he plays 2700+ people. Until you're that level, don't believe the stories :-)

i'd play the SMG