Is anyone on here good at chess? And how do you get better?

I used to play with my grandad when I was a kid, I used to think he was a sort of Bonnyrigg grand master at it. When I beat him I celebrated like David Gray in 2016. Unfortunately as i got older, and proper chess players were handing my erse to me in 9 moves, i realised neither of us were up to much Ive been watching stuff online about various openings and so on,i like getting my knights into play and playing the 4 knights game or variations on that, but I think im just being let down by not paying attention. Or sheer stupidity.