Yes, you grabbed a build of Panda that was compiled for Python 2.6. It will not work with Python 3.6. You would need to grab a build of Panda that is specifically marked “py3.6” (there are some listed).
It may be easier to install Panda3D with “pip”, using the following command:
python3 -m pip install --extra-index-url https://archive.panda3d.org/ panda3dThis will make sure to grab a build that will work for your version of Python. Although the pip packages are a bit experimental at this point, so let me know if you run into any trouble.