Kingdom Eubacteria is the only kingdom found in the Bacteria Domain. Most bacteria, especially familiar bacteria, are Eubacteria which is the largest of the kingdoms. These microbes live in places that are not extreme or what we will call good conditions.
Most Eubacteria are consumers or heterotrophs, many of which feed on dead organic material and are decomposers-thankfully! Not all are decomposers, some are parasitic and feed on other living organisms. Ever experience strep throat or cavities?
Some Eubacteria, like the cyanobacteria, contain the green pigment chlorophyll and carryout photosynthesis. Remember, we call organisms that make their own food producers or autotrophs.