See Seeds' Table. Read tables such as this with care. The five most common elements are H, He, O, C, N with Ne where I list them by their concentration. Note the dominance of H and He. Most answers were poor paraphrases of the text.
Red giants are very luminous but rare.
Red dwarfs are of low luminosity but common. The luminosity difference between a giant and a dwarf is so great that a quite distant giant is brighter than the nearest dwarf. Same is true for hot stars like Rigel and cool dwarfs like Barnard's star. Very few complete answers. Many spoke of observing a shift of a nearby star as the Earth orbited the Sun.