White moves first, and in doing so decides what kind of game it will be. Collected here are the openings played with the white pieces: the open games after 1.e4, the closed ones after 1.d4, and the flank openings 1.c4 and 1.Nf3. Every one of them comes with a move-by-move walkthrough on the board.
The first move is White's only advantage, and it does not really lie in the extra tempo. It lies in the right to set the subject. Until White has moved, the opponent does not know whether the game will be an open fight with early exchanges in the centre or a slow positional squeeze. Black spends the game replying; White proposes.
There is a practical consequence: as White you only need one first move and three or four schemes behind it. You do not have to prepare against everything in existence - you need to know what you are doing against the most common replies. A White repertoire is almost always more compact than a Black one.
The advantage itself is small: large databases give White roughly 52-55% of the points. That is not a win, it is the right to impose a comfortable position first - and it is exactly the sort of margin preparation can turn into a result.
Three workable starting points for three different temperaments. Take one and play it for at least a month - that beats knowing five of them superficially.
The Italian Game after 1.e4 e5: the pieces develop to natural squares, the plans are clear, and the standard tactical shots turn up in every other game. The other option is the London System - one set-up against nearly everything Black plays.
1.e4 leads to open positions, early exchanges and direct play against the king, which builds tactical experience faster. 1.d4 gives closed positions with long manoeuvring. Beginners are usually pointed at 1.e4, but there is no real difference in strength between the moves.
One first move and three or four schemes behind it will carry you to a confident club level. You widen the repertoire when a particular reply starts causing trouble regularly.
No. Large databases give White around 52-55% of the points - a small advantage, not a decisive one. It means only the right to choose the character of the fight first.
At club level it pays far more to understand the ideas: where the pieces belong, which pawn break is coming, what the middlegame plan is. Memorised lines run out by move five or six, and the game has to be played after that.