Best opening moves


as you didn't clarify if you searched for openings for black or white,I'm just assuming you mean both.

i would recommend as an easy opening for white the london systems, not much theorie, easy developement independently of blacks opening.

and as you are a beginner you should definitely also learn the Kings indian both attack and defense for Black.

Chess Openings Resources for Beginners and Beyond...
https://www.chess.com/blog/RussBell/openings-resources-for-beginners-and-beyond
https://www.chess.com/blog/RussBell

https://www.chess.com/openings has a lot of good beginner content for this, and yes, London System is great for beginners.
Colle System starts at five moves with the fifth one castling. It can get very complex, but the basics is a center pawn push, no closed positions and no hanging pieces in the beginning. There are a couple of potential knight forks that you have to be aware of though which are managed in the system. It also favors trades which beginners tend to do anyways.

Opening for White: London System
Opening for Black vs. E4: Sicilian
Opening for Black vs. D4: Nimzo-Indian
If any other move vs. white/or black try to copy if you can.

If you mean system based openings where you can play the same setup against almost anything your opponent throws at you then there are really are limited to:
White: London System, English opening (you can lead the game to a typical g3 fianchetto setup though it can deviate pretty early on)
Black: King's Indian setup (though if you play it against e4 it may lead to a pirc)