The lessons you've just completed teach you, at a high level, everything you need to know about Unity in order to build our Monster Siege / Tower Defence game.
However, if you want to dive deeper with the basics of Unity and understand it better (whether for your own general knowledge or so you can use the knowledge to make your Tower Defence game even better than the one we're building in this course), there is an Optional Appendix in this course that teaches you just that!
If that's what you want simply scroll down to the last section of this course entitled "Optional Appendix: Unity Basics", complete the lessons in that section, and then come back here to continue!
Otherwise, let's keep going!