A good start is to build something cool with their tools e.g. using the Agent CLI or perhaps an extension
Its a bit self-promotiony, but I built my own UX Wrapper around the Cursor Agent CLI in the ‘Built with Cursor’ forum to help my workflows managing projects. Its actually not that difficult to do and is a lot of fun - in fact I barely open up the actual Cursor app anymore.
I highly recommend it and you’ll learn a lot about how Cursor works behind the scenes.