That depends upon what your needs are for the course, but it looks like you’ve outlined that:
Your upsells are going to be challenging with Webflow. That all has to do with the Webflow Ecommerce platform. A couple of options are different products or variants on the same product. You’ll need to distinguish between one-time payments or subscriptions (and how they specifically integrate with Webflow Memberships) to fully understand those challenges.
You’ll also need to consider the sign up flow. More details here:
It’s a bit of a heavy-lift in Webflow since it’s not something they natively support, but it’s doable with either custom code, 3rd parties, or both.