Yes! All the lessons are available to you forever.
Here's how you can access them.
Visit you student dashboard to find the course you'd like to revisit. Here's the link for your dashboard: https://courses.dts.edu/enrollments
Click on the link for the course:
If you are on a laptop or desktop, you may see this screen:
You can click on any of the lessons on the left to revisit them.
If you are on a phone or tablet, you may see this screen:
You will need to click the three lines in the top right corner to see the list of lessons.
Then you can choose the lesson to revisit.
You can even retake quizzes using this method!