Spores are not seeds. A seed contains a small form of a plant, plus some food to help it get started, wrapped in a hard shell. A seed is made of many cells.
Most spores are single cells protected by a cell wall.
There is no microscopic fungus inside a spore. A spore contains all the chemicals needed to make its kind of fungus. When conditions are right, the spore starts to grow and creates a web-like mycelium, the fungus individual. Clarendon Press, Oxford.