Best Chess Opening For Black And White 200-600 ELO?

One idea is a simple system opening that can be played as both white and black.

Example as white:

1)Nf3,... 2)g3,... 3)Bg2,... 4)0-0,...

The king is safe, two minor pieces are developed and then you can concentrate on appropriate pawn moves depending on your opponent's responses.

This may allow your opponent to build a big center and it does resemble a hypermodern style of play but at 200-600 elo it is not that big of an issue. Just play and start concentrating and learning other areas of chess principles like middle game and endings.

White players should start with e4 or e5 if they're weak players

For me I'd say King's pawn, Queen's pawn, King's Gambit or Queen's Gambit. Those are probably my favorite 4 openings as white

White:

1) London System - It's simple and fantastic

2) Italian Game / Guicco Piano - It's simple and positional

3) Four Nights Game

Black:

1) Caro-Kann

2) French - only if you are thorough

3) King's Indian

Petrov's Defence is a solid opening. It's hard to play against and you can change it to the Three or Four Knights Game if you want. The Stafford Gambit in the lines of the Petrov's is good too. Also, it stops the Scholar's Mate.
The King's Gambit is great too because no one knows what to do against it. If they accept, you can do the Villemson Gambit. If they decline with the F pawn, you trade and then slaughter the king. If they decline with the D pawn, you exchange the pawns, develop the king's knight and the position is generally considered better for white because 2 central pawns is better than 1.

Play e4, d4 , or Nf3 when you are white in a game