Openings-1.e4 or 1.d4

Which is better for non Masters?

e4 is basic... d4 will be better for masters

Otherwise both are great

Many masters play e4 although

But better will be if you practice e4 only

Because most beginners play 1.e4, and because a lot of people say that 1.d4 should be played only by masters, you have a nice advantage if you begin with 1.d4. There is well possible that your opponent doesn't have any idea how to play against it, especially if you play 2.c4. However, you should build up a repertoire based on it. One of the best ways to do so is to go to Chessable and try there some lines and see if you like it. In the lower levels you will often win a figure for a pawn, or a whole figure, or get the ideal centre for free. The few attempts to complicate the game with gambits are not scary at all, and in some you get an almost winning position after a couple of moves. As I said, you have to know how to play 1.d4, but the same applies to 1.e4.

Good points torrubirubi but I don't want to rely on the surprise factor. I want to play the move that will lead to the better game, whatever level I happen to be in.

e4 is considered better for beginners as it teaches them the importance of space and open diagonals

d4 will become easy to understand eventually

---

1.d4 and 1.4 are probably rather equal concerning keeping whites slight advantage. My argument for 1.d4 is more related to the fact that you can play 2.c4 without any risk before playing Nc3. In 1.4, if you want to play 2.f4 you should be ready to sacrifice a pawn and play a chaotic game. 1.d4 players have more control over the position, and if black wants to complicate things he has himself to sacrifice something or play a horrible position, like in the Englund Gambit. My students tell me how they win against players with much more experience just by playing natural moves.

In general, 1 e4 leads to a more-open game more frequently than 1 d4 and, since lower-rated players rely more on seeing tactical combinations than seeing imbalances they can strategically plan with, open games tend to fit lower-rated players better.

But it's still just a matter of degree.  If you can exploit N-Outposts, backward and Passed Pawns, open files, exposed Kings, etc. better than another player with a similar rating, a closed game against that player benefits you.

Additionally, 1 d4 doesn't guarantee a closed game.  I've always played 1 e4 until this year and have played a few London System Games as White (1 d4 2 Nf3 3 Bf4) because it's basically the mirror-image of my favorite Slav or Caro-Kann Defenses and I want to see what it's like to play those positions with the advantage of having the first move.  It tends to make the games more open than the Slav and is fine, I think, even for open-game lovers.

The October 2017 issue of Chess lists the top twenty openings compiled from a list of 4192 August games where both players were rated over 2400 Elo. One can not take position on this list too seriously because it is greatly influenced by how the openings are grouped. For example, all the Retis are grouped together, while English is separated into 1...c5, 1...e5, etc. Nevertheless, for what it is worth, some of the list entries are: 271 Retis, 232 King's Indians, 172 Caro-Kanns, 165 Nimzo-Indians, 126 Najdorf Sicilians, 126 Slavs, 118 declined Queen's Gambits, 100 Queen's Indians, 98 1...e5 Englishes, 94 1...c5 Englishes, 93 Kan Sicilians, 81 Tarrasch Frenches, 77 1...Nf6 Englishes, 73 Guioco Pianos, 67 1...e6 Englishes, and 66 Moderns 

Try www.365chess.com Opening Explorer.

Go with 1.e4 it's "best by test" as Fischer would say.

play both and see which one you prefer.