If you play e4 you will find that many opponents will play c5. You also have to be prepared for e5, and to a lesser extent e6.
Playing 1.e4
The 7 most critical responses to learn in order of importance:
1...c5 - There are a bajillion Sicilians to know. Even if you don't play the open Sicilian, the non-forcing nature of most anti-Sicilians gives Black numerous sound options, so going Anti doesn't solve your problem
1...e5 - Again, multiple possibiilities. Against 2.Nf3, you have the Petroff, Philidor, and Main Line Open Games. Agaisnt 2.Nc3, you have the positional 2...Nf6 and the tactical/aggressive 2...Nc6. Against the King's Gambit (unsound), you have accepting it and declining it, etc.
1...e6 - French Defense
1...c6 - Caro-Kann Defense
1...d6 - Unknown, but most common is Pirc or Philidor Defense
1...g6 - Modern Defense
1...Nf6 - Alekhine's Defense
Suggestions can be found in:
Openings for Amateurs by Pete Tamburro (2014)
http://kenilworthian.blogspot.com/2014/05/review-of-pete-tamburros-openings-for.html
Chris Baker's A Startling Chess Opening Repertoire
http://www.theweekinchess.com/john-watson-reviews/more-nco-gambits-and-repertoires
John Emms's Attacking with 1.e4
https://web.archive.org/web/20140627003909/http://www.chesscafe.com/text/hansen29.pdf
http://www.theweekinchess.com/john-watson-reviews/one-book-repertoires-online-bargain
Beating 1 e4 e5 by John Emms
The King’s Gambit by John Shaw
http://www.chessvibes.com/?q=review-the-king%E2%80%99s-gambit
The Ruy Lopez: Move by Move by Neil McDonald (2011)
https://web.archive.org/web/20140627022042/http://www.chesscafe.com/text/hansen153.pdf
Kaufman's original repertoire book, The Chess Advantage in Black and White
https://web.archive.org/web/20140626223458/http://www.chesscafe.com/text/hansen62.pdf
http://www.theweekinchess.com/john-watson-reviews/in-the-beginning-there-was-theory
Sam Collins's An Attacking Repertoire for White
https://web.archive.org/web/20140627122005/http://www.chesscafe.com/text/hansen66.pdf
Neil McDonald's Starting Out 1.e4
https://web.archive.org/web/20140627032909/http://www.chesscafe.com/text/hansen89.pdf
http://www.theweekinchess.com/john-watson-reviews/opening-books-en-masse-part-3
Chess Openings for White, Explained by Alburt, Dzindzichashvili & Perelshteyn (2006)
https://web.archive.org/web/20140627032909/http://www.chesscafe.com/text/hansen89.pdf
https://web.archive.org/web/20140626210017/http://www.chesscafe.com/text/hansen132.pdf
http://www.theweekinchess.com/john-watson-reviews/good...good...good...disastrous
A Chess Opening Repertoire for Blitz and Rapid by Evgeny and Vladimir Sveshnikov
Coming soon:
Playing 1.e4 - Sicilian & French by John Shaw
Playing 1.e4: Caro-Kann, 1...e5 & Minor Lines by John Shaw
A Simple Chess Opening Repertoire For White by Sam Collins
The problem is your rating, there are a lot of people in your rating range that know nothing about opening theory and even the ones that know usually play some pretty offbeat opening, so at your level you will find anything from main lines Sicilian and Ruy Lopez to the Scandinavian.
I take a different aproach, you cannot possibly study all the openings and variations, so go play a game, see what opening your oponent plays against you and after the game take a look at it. Little by little you will improve your opening knowlegde.
So, study the first few moves of the main openings (Sicilian, Ruy Lopez, French and Caro-Kann) and go play, maybe your oponent will play a Najdorf, then after the game you take a look at the Najdorf, so you are prepared for the next time someone plays the Najdorf and each time someone plays the Najdorf you study a little bit further, maybe they played a variation you weren't aware of, so study it.
Hi everybody, how are you? I have a really simple question for you. I want to change my white opening 1.d4 to 1.e4. How can i adapt to this as fast as possible? And which black replies should i study? Thank you very much.