Why does synchronization of the shared folder not work?
You likely booted the virtual machine through VirtualBox. The virtual machine must be booted through Vagrant by executing vagrant up inside the directory containing the Vagrantfile.
Why does Spark.ipynb throw long errors?
Apache Spark likely does not fully support your Java version. Remove the current Java installation and install an older one.
sudo pacman -R jdk11-openjdk sudo pacman -S jdk8-openjdk
How to handle files containing a whitespace?
Either you escape the whitespace with a backslash or you put the path in double quotes.
mv path/to/source\ file.example path/to/destination\ file.example mv "path/to/source file.example" "path/to/destination file.example"