Do I have to format the drive first, and how do I do that?
How do I get a Linux system onto that drive?
How do I get easy access to both drives?
I do hope someone has the patience to help
No the drive can be formatted during install.
1 thing you have to be careful of is the fact that both drives are identical as far as size, so it can be easy to write to the wrong drive.
Also you said windows cannot see the drive check it in disk management.
Also during install linux does not label drives the same as windows, It will see your drives as sda & sdb & so on.