My first two lessons (also started teaching it this year) were learning some constellations.
In the first lesson they found images of the constellations and sketched them, followed by a game using black sugar paper and white-chocolate buttons (essentially one person in each group lays out the stars and the first group to get it right eat the buttons they used, the first group to run out of buttons wins – sort of an astronomical pictionary).
The second lesson was the circular part of a planisphere cut up into a jigsaw of the constellations and photocopied. They cut out the pieces and see how the constellations fit together. They then glue this down onto card accurately and use it to make their planisphere.
All the best