Opening Recommendation
Play 1. d4 and go for the london setup. Many of your opponents will likely expect 1.e4. The queens pawn opening already confuses them. You can also play the hippo setup. You can play it quickly and your opponents will probably waste time thinking.
But if you are playing beginners then shoot for the scholar's mate setup. It is unsound but many chess players at sub 800 rating still fall for it.
Nimzo-Indian will help with a solid, but not the most reliable, but good enough opening against d4, but that’s only against d4. For against e4 and while playing white maybe, against e4 French is solid, but if that is too boring then e5 is good enough, but if you actually want something that the normal person wouldn’t know and is very aggressive, but a good enough amount of solid is the accelerated dragon and in honor of Danya you can learn it from him and some other people. For white the Spanish is fine, but can get complicated in mainlines and some sidelines so the Italian can work, but it is very known so can be countered very easily so you also have the choice of the stonewall. Not hard, not easy, not medium, but in that good spot between medium and hard and is solid and aggressive too if you want. The Colle-Zukertort is pretty similar to the stonewall so it’s like 50/50, depending on which you like better. If I were to suggest then this would be it.
As white: Colle-Zukertort
Against e4: Accelerated dragon Scicilian
Against d4: Nimzo-Indian defense.