Do them! You can't learn programming by just reading about it.
There are also fill-in-the-blank questions. Do those, too.
Lessons have content, and then exercises.
One way to work is to scan down the page, and find an exercise. Then work backwards up the page, just reading content that looks like it has to do with the exercise.
Not a good idea. You'll miss stuff you need to know.
The pages are written to be read from the top down.
Read pages from the beginning to the end. Don't skip stuff. If you do, you'll make things harder on yourself in the long run.
Your virtual class
Here are your virtual classmates.