If you do not know OOP or python to begin with, i would start with that and forget about game design for awhile. Otherwise your going to have to do it anyways. The structure that they show in invent with python gives bad programming practice.
I would start with some basic code, getting a windows displayed, and drawing a rectangle etc. stuff like that, by using the invent with python book and internet resources. Then convert it over to OOP and structure it as mekires pygame samples repo does, using classes. Become fluent in converting these over to classes (because a lot of examples DO NOT use OOP), and start hacking away at small simple accomplishments. Dont try to make a full fledged game the first go around. Start working on how to: adjust to fullscreen, blit images to the screen, scale images, chop spritesheets, animation, event handling, etc., as that alone will take you a bit to get accustomed to.