Mario Bros

A few days ago I got a Mario Bros game on my switch, it's the classic Mario Bros so I know some of it but I'm still not very good. For example I haven't even gotten past the first world, while there's 8 worlds. My parents used to play Mario a lot but with my button layout they haven't gone past 1-1 (world 1 level 1). I'm getting better and I think I'll get to world 2 soon. The last thing is that I don't know how to activate 2 players so that's unfortunate.