Click on settings
In the Advanced
tab, you can choose to allow clipboard sharing between host and VM
I believe the host is your MAC and the guest is ubuntu, i'm choosing
Host to guest
In the Systems
tab you can change the base memory. Also here is the Boot Order
just use default for now
In the Processor
, choose 2 if you did not intially
In the Display
tab, put Video Memory
full, and enable Enable 3D Acceleration