Oscilloscopes allow you to visualize how electrical signals change over time. This means you can measure periodic and transient signals, which might be too fast for your digital multimeter to catch. Oscilloscopes can be indispensable for debugging circuits.
In the video, I talk about why 10x probes are useful, how to tune the compensation capacitor in a 10x probe, how to measure periodic signals, and how to set up a single capture trigger for a transient signal. I hope that this works as a starting place for someone who might be just beginning with oscilloscopes.