How to lubricate a bicycle cable so I'm very new to all this, so I don't know a lot. My mountain bike will no longer shift gears, I've been told this is because my cables need lubricated, but I have no idea how to do this, so, how would I do that with a spray lubricant?

And please keep in mind, I don't really know anything about bikes.
It is always strongly recommended (by the manufacturers, I read it on Shimano's instruction sheet) not to lubricate a new cable when you're installing it. The reason is that both cable and housing are teflon-coated at the factory and lubrication could destroy that. When a cable loses the ability to move freely it is best replaced together with the housing.