Hi Norm (?) and welcome.
I have downloaded the manual for the 770 and PHEW! Quite a piece of kit! It appears to be able to record and play via USB to a computer (PC?) and an SD card. I have also never seen a kbd with a VGA connection for a monitor? Shame that only applies to the 970 AFAICT.
Between all the bells&whistles on the Yamaha and Cubase 10 you have got a LOT of reading and experimenting to do. I suggest a very systematic approach, get a big diary!
You say you have a lot of questions? I bet! Can I suggest you frame them one at a time as far as possible? You have made a great start by giving the make and model of the kbd and the software you will be using. The Yamaha is virtually an "Audio Interface" on its own but IMHO an actual, dedicated AI would add immense flexibility to the setup, especially if you wanted to use a microphone. Or indeed one of the new breed of USB mixers.
How at present do you listen to the 770?
Dave (NB, I am not a keyboard player, just and old 'tronics tech who has dabbled for a talented son)
