Share clipboard Host vs. Guest

After login to your account, from the VirtualBox's main menu, click on Devices then "Insert Guest Additions CD image".

When the Guest Additions image is mounted, click on the autorun.sh to process with the installation.

Next step, from the main menu, click on Devices, then Shared Clipboard -> Bidirectional

Reboot your guest OS.

Reference:

https://www.liberiangeek.net/2013/09/copy-paste-virtualbox-host-guest-machines/