Without trying to tell you how to live your life, we do recommend for your convenience to set up SSH access to the VM (e.g. copying SSH keys for faster access), as you will need to use multiple terminal shells at the same time. The Ubuntu system in the VM comes already equipped with an SSH server on port 22.
ONOS provides you a convenience script to do so
$ ones-push-keys <Ip_of_machine>
This walkthrough demonstrates the necessary steps and commands to run a network of BMv2 devices in Mininet, controlled by ONOS using P4Runtime.