Elementals can be of either good or bad intentions. It depends upon the elemental and how you meet them. The basic types are air, water, fire and earth. They have elementals that can be considered blends of the different types of elements. The best thing to do is to leave them alone unless they come up to you and volunteer to help.
Planetary spirits are next.
They also have a dual nature and there are good and bad spirits. Some demons have planetary and elemental aspects to them. The planets are Jupiter, Mars, Saturn, Moon, Sun, Neptune, and Uranus. A good book on astrology or candle-burning will tell you the different aspects. You can tell by the subjects listed why they are considered to have a dual nature.