first of all the basics would be the rule of thirds. most of the mirrorless cameras out there allow you to turn on grid lines to make it more easy for you to line stuff up on the thirds.
remember though you need to balance an image generally you have 2 subjects in an image. a primary and a secondary both of which if possible putting on opposing thirds so the image maintains balance.
the same can be said about the balance of light and dark. so if you have a mass of darkness on one side or the other the image will feel heavy on that side of the image so try first of all just to achieve balance in the image while keeping on the thirds.