Just fill the header tank up to the max when the engine's cold. It may not have been full from new. Have a check on the water hose connections and the header tank pipe are all OK.

Oil - yes it can use some - quite normal unless you have plumes of white smoke behind you and a rattle between your legs! Be sure to have the engine warm and don't screw the dipstick in, just sit it on top of the threads with the bike upright.

My 955 Triumph triple used 1/2ltr in less than 1k miles - quite normal they said. Well at least the engine gets nice fresh oil regularly..