Choosing Gambits

For now, work on your game and understanding of opening principles. But working on your overall game is more important than working on the openings. Carlsen can get away with playing dross openings sometimes because he is such an excellent player, not because the dross openings magically become good. 1. e4, e5; 2. Bc4 intending 3. Nf3 (Giuoco Piano but avoiding things like 2. Nf3, f5 chaos) is reliable, some system like 1..., b6 against everything (apart from White moving the g-pawn on move 1) can be solid. There is no such thing as a Perfect Opening. Just openings that get you into a nice position you can play well. And you find out what they are by working backwards from what sorts of middlegame you play well. Gambits I'd recommend avoiding until you can truthfully say, "I am good at handling the initiative and am able to find tactically critical moves reliably better than the people I am playing against".