A pyramid can have an infinite number of sides other than two. If it has one (or an infinite number of) side(s), it is considered a cone. If it is, for example, a hexagonal pyramid, it will have six sides. A triangle-based pyramid has three sides. A square-based pyramid, commonly the structure used by ancient Egyptians, has four sides. There can be pentagonal pyramids, hexagonal pyramids and so on.
That depends on the base. Count the edges of the base polygon and then add 1 to determine the total number of faces, including the base. E.g., a square pyramid has 5 faces in total.