This course does require a basic understanding of Web programming; if you are new to Web programming or need a refresher course, I would highly recommend spending time to go through the following tutorials on W3C:
Object-oriented programming (OOP) is a programming language model that organizes software design around data, or objects, rather than functions and logic. An object can be defined as a data field that has unique attributes and behaviour. The Tableau Extension Library is an Object-based library, and therefore you will need to be familiar with these concepts before progressing.
You can go through the course and copy what I do, however, by understanding these concepts, you will maximise your learning.