I'm glad to hear that you have an appointment with U of Michigan. I hope that you are as happy with your medical team as I have been with mine.
I live about a 40-minute drive from U of Michigan (I am in SE Michigan) so it is probably not as far as you. Will your CT scan be done locally?
I have done some video appointments with U of M and they will provide written instructions and suggest that you practice the process a bit before your appointment. You can also call for their support team if you do not understand the directions.
Do you have a grandchild/teen neighbor or other "techy-person" who might be able to help you get your computer set up?