A student asked me for suggestions regarding online resources for learning and practicing Python.
Here is a link to a page that lists 7 free online Python courses/tutorials. I haven't tried these out myself.
As Dennis Ritchie said, the only way to learn a programming language is to write programs in it. Ideally you should spend some time coding every day, even if it's only a few minutes. But a natural question to ask is "What should I program?"
Our textbook has lots of appropriate short exercises, particularly in the first few chapters. Over the weekend I'll make some specific suggestions, but if you read the chapters and do the exercises you'll be flying in no time.
Another excellent source of interesting programming tasks is Project Euler. This site, named for the most prolific mathematician in history, has been collecting and posting programming problems for 20 years. You can access the problems by going to the site and selecting "Archives". Many of the problems can be solved with very simple programs ... but be warned, sometimes a simple program will need a lot of time to find the answer to the problem.
Here are some other sites that list programming tasks and/or challenges. I am not personally familiar with these and so I am not recommending them ... just drawing them to your attention:
https://www.w3resource.com/python-exercises/
https://www.practicepython.org/
http://blog.smartbear.com/programming/7-silly-programming-challenges-to-do-for-fun/
https://www.reddit.com/r/dailyprogrammer