Um, it was never explicitly covered. Not enough time. I just read the back of the textbook. Let's see: after we'd finished doing the Controlled Assessments and we were into Past Paper Practice, I used to write practice ones incorporating new bits of grammar, and ask the tutor to point out any errors. So that would have been in early June. (I did Life of a Celebrity and made up a band called Atomisches Kätzchen, and their new album Nichts Neues.)
To be honest: "you capitalise anything after nichts or etwas and add -es" will serve you well for years, no additional understanding required! Or even just memorising "nichts Neues and etwas Interessantes"