Does anybody know a solid opening for white

Tactics before strategy. Or rather - Tactics before 'positional'.
But that doesn't mean you have to play e4 openings to learn tactics.
What is the main issue of the openings?
Is there a single main issue?
Well you have to play it. Its part of the game.
And for many beginners or people contemplating playing chess ...
it keeps them out. Out of the game.
Or means a flat learning curve.
Chess has different phases and elements -
which part of chess - when time is invested - has the lowest return on investment?

No

if you play 1.f3 and 2.g4 you will have a solid chance of leaving the round earlier than anyone else

Especially if black played e5 or e6 on his first move - in response to 1) f3 by white.

London System?

1. g4, the Grob.