Natural world: atomic structure. Structure of the solar system. Phases of the moon and eclipses. Elementary treatment of circular orbits under gravity including orbital speed, radius, period, centripetal acceleration, and gravitational centripetal force. Satellites; geostationary and polar orbits.
Much of this material might actually be new for you, depending on which GCSE course you did. It is important to get a good understanding of the simple orbital mechanics (see these notes), and this is also a good way of getting to grips with circular motion (see the mechanics section).
Answers to questions about the ‘natural world’