Since you only have one serial port that is being used for debug, upload etc download the software serial software and use it to communicate with your MonkMake 7-segment display.
I have found a different info, that the Nano Every has more than one serial port.
D11/D12 can be used as MOSI/MISO ports, according to the documentation at page 9:
I have also found another page that says that it has 4 serial interfaces, you just need to enable them, as it is not default.
My question is rather be that. If it says that 9600 baud interface. Do I just set up D11/12 as serial 1-2-3-4 in void setup(), and just simply serial.println the text that I want to make appear?
Or is there something more complicated magic here?