Take the Star example and modify it as follows. Each exercise is meant to be separate, and you should build each one from the unmodified Star example.
Make the drawn star upright, so that one of the vertices points straight up.
Make the drawn star six-pointed. Edit: This is harder than I thought. Skip.
Make it so that each star is a bit bigger than the previous one.
Make the drawn shape a pentagon instead of a star.
Make the drawn shape a regular polygon, where each polygon has one more side than the last, starting from 3. That is, the first shape drawn, at the first click, is an equilateral triangle; the next shape is a square; the next shape is a regular pentagon; and so on.
Solutions to these exercises are available in the Class 8 examples on the syllabus.