Our school made us do a transformer practical. It is the same every year. So maybe ask past students of what you can expect. Anyhow, our practical was based on setting up a transformer correctly. We measured Vp against Vs, graphed it. That was pretty much it. We also were asked to answer a series of questions about transformers. (Write down its efficiency, explain the role of the soft iron core, eddy currents etc)
What helped me was a solid understand of the topic.