Regarding what to shoot, there's only one rule I follow, in the main.
I shoot whatever I find interesting, or curious, or enchanting, or unusual, or specatular, or confronting, or revealing, or memorable, or fascinating, or exciting, or deplorable, or disgraceful, or newsworthy, or meaningful in any way, or simply beautiful.
There are occasions when I may humour someone and take an obligatory shot of a scene that doesn't interest me.