My advice would be to look up "Earth" in any currently published encyclopedia, in any language. It will immediately alert you to the fact that the object so designated is an oblate spheroid, third in orbit about a star, designated the Sun, or Sol. Said object is a planet, approximately 25,000 miles in circumference, with one satellite, designated the Moon. To date, it is the only known object in space to have life, although it is possible that life MAY exist on Mars in microscopic form. Usually said encyclopedia will contain a picture of said spheroid, so designated as Earth. Occasionally, one might find the Moon pictured as well.
I would recommend looking under the Volume of whatever encyclopedia you use that is designated to the letter "E". That will assist you considerably. World Book is excellent for its pictorial aspects. And it still publishes a hard-copy volume. Britannica is better in terms of information, but is now only found electronically.
There. I have just satisfied your request for citation of sources. Enjoy your research.