What should I learn after this course?
What do you want to do next?
Or, ask yourself what you most want to achieve from learning Blender 3D?
What courses will help you achieve your goals?
If you want to be an animator, focus on animating and rigging for example.
If your totally new to Blender, all the fundamentals are a must watch...
The Fundamentals to become a skilled Blender artist Playlist is the place to go so you don't miss anything.
After that you could continue on with the Modeling in Blender 101 Playlist.
Yes I'd go with the fundamentals, even if you just want to animate I'd say start with the fundamentals of modeling, it'll give you a good bedrock that I think is necessary. For me it would be this course:
https://cgcookie.com/courses/fundamentals-of-3d-mesh-modeling-in-blender
And then the bootcamp: