Welcome back. If you have done all of lesson 1 like its supposed to be done. Then spent time really studying and getting to understand perspective from the books then congratulations are in order. No really give your self a nice solid pat on the back. A lot of people think they want to be artists but will never even put in this much work. Plus now you should have some solid hand eye skills and perspective skills etc to take with you on your journey of learning art.
OK now that you have a good understanding of perspective lets put it to use. For the first exercise we are going to redo one of the first exercises of the course. We are going to setup a your cube again just like as before and do a line drawing of it. So set it up on a table with a solid background. And setup your easel at a slight angle or even vertical if you like. Setup your paper up. And now draw the cube. But this time it should be much easier as you understand perspective and how to draw a cube. If you do not understand these things you need to go back to the books from the introduction.