What are compounds that contain only carbon and hydrogen?
These are known as organic compounds. They are called organic because they are found in living, biological substances. The opposite would be inorganic compounds that are found in abiotic (nonliving) substances such as rocks, gems, or salts (such as quartz, mercury, granite, limestone, diamonds, etc.).
Monomers (mono = one) of organic compounds for chains of longer organic compounds called polymers (poly = many). When only single bonds are concerned, hydrocarbons (substances made of only carbon and hydrogen) follow the formula of C(x)H(x+2).
Hydrocarbons can also contain other elements (sulfur, bromine, etc) or functional groups (alcohol, ether, amine, etc) that shoot off of the main branch.
Please see the attached links for a full list of types of hydrocarbons and the naming convention for them.