Congratulations! From this point, you should start to feel more comfortable with Python and should soon be solving problems with the language.
If this is the first time you've read through a programming book, you've probably forgotten most of the material. Don't fret: that's normal. Learning to program, as with any skill, requires repetition and practice; over time, you begin to absorb the material, and that's when the real learning starts.
Don't take a sequential approach when learning to program. You won't master all the material in this book on the first try. Take a circular approach to learning, and you'll have "ah ha" moments the second, third, or even fourth time you approach a topic. Use other resources such as introductory-level books and videos. The second time around, you'll surprise yourself with how much better you understand and remember the material.
Most importantly, don't stop coding and practicing.
Beware of other resources if you plan to go through Launch School's Core Curriculum. Sometimes, those resources can conflict with how we teach at Launch School. They can even be incorrect or be based on outdated information. Regarding Core, especially during assessments, our material trumps other resources.