No, you don't have to pay separately. Becoming a paid member get's you access to both the courses.
During the launch of the course, I announced that I would make 1 video of the course publicly available every week. The first video was upload on 28th June, 2023. So depending on when you're reading this, either all or some of the videos have been made free on YouTube.
However, only paid members get access to the Starter and Completed Figma File which can be duplicated and played around with. I will also be updating the Figma file as and when Figma announces new features and updates.
If you're not in a rush to learn about Design Systems, that's absolutely alright. However becoming a paid member gives you access to the Product Design Course as well. So you might want to check that out.