You can find unicellular fungi, and macrocellular with some centimeters height but all of them are eukaryotes.
Its cell walls are made from chitin and not from cellulose, like plants.
All fungi are heterotrophs this means, they live from organic soil. They expel enzymes to dissolve and then absorb organic substances.
Because fungi don't have chlorophyll, they can't do photosynthesis and because of that they can live without sunlight so, it's common habitat are dark and wet places.