The twelve houses run counter-clockwise from the Ascendant and cover, in order: self, resources, communication, home, creativity, work and health, partnership, shared depths, meaning, vocation, community, and retreat. Learn them as places rather than as topics — the twelfth is not 'bad', it is the room behind the stage.
The most common beginner worry is an empty house. Ten planets cannot fill twelve rooms, so at least two are always empty, and an empty house simply means that area runs on the sign on its cusp and the condition of that sign's ruler. Nobody is missing a love life because the seventh house is empty.
The useful move is the opposite one: find the stellium. Three or more planets in one house tells you where the biography concentrates. Nine times out of ten it is the first thing worth saying in a reading.