This lesson won't teach any electronics, really. Its more for making sure that everything is setup and ready for the future lessons. It will verify the Circuit Playground is working as intended and that the computer you are using is compatible.
Think of this tutorial as the 'home base' of your journey. If things ever get into a weird spot come back here and re-verify this lesson!
One of the most important skills you'll have to learn is that when things go wrong (and they will, tons) come back to the most basic assumptions. This is a little bit of the "are you sure its on" of electronics. It's surprising how many skilled engineers will spend hours debugging a circuit to realize that...it wasn't plugged in!