best first move

As white, it depends on what opening you want. e4 or d4 are the most common.

Hi! My name is Lauren Goodkind and I’m a chess coach and chess YouTuber based in California: 

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You want to move e4 or d4 on the first move.  That's ideal.  Some people will move out the knight for the first move.  

Beginners ought to focus on control of the center when they start learning. The most common start is e4 and d4.

Don't try to hold on to the c4 pawn with dear life if you ever touch the QGA (not recommended)

You want to control the centre with your pawns!

First 2 pawns d- and e-, then 2 knights, then 2 bishops, then castle O-O to bring your king to safety and to connect your rooks and last but not least your queen.