It would be impossible to cover the entire topic of first aid in a document of this type, but you should instead look into reading a good book on the topic (see section 10.3 Books) and perhaps even take course.
The basics of first aid under primitive conditions are no different than under modern conditions, with the possible exception that the mateials at hand might differ. Thus you might use sphagnum moss instead of field dressings to staunch bleeding, fresh pine resin on small wounds instead of bandaids, etc, but the principles remain the same.