Before we jump into creating large-scale scripts, you need to understand the errors that can be produced. If you start creating scripts and generating a bunch of errors, you may get discouraged. Keep in mind that Python does a pretty good job at directing you to what you need to look at. Often, however, the producer of the error is either right before the line referenced or the function called. This in turn can be misleading, so to prevent discouragement, you should understand the definitions that Python may reference in the errors.
Reserved words, keywords, and built-in functions are also known as prohibited, which means that the name cannot be used as a variable or function. If the word or function is reused, an error will be shown. There are set words and built-in functions natively within Python, and depending on the version you are using, they can change. You should not worry too much about this...