I don't play that much tbh, and I know very little opening theory. But I have been trying the Reti, and it seems to work quite well. I've also tried the Stonewall Attack, which is basically white playing the line of the Dutch defense. Very solid and requires little detailed knowledge of move orders, but a bit passive and tricky to attack from.
I wonder if relative novices are best off avoiding opening with e4 as white, in order to avoid the Sicilian Defense? (Since it's very heavily analysed, and quite easy to make mistakes in)