Thanks for letting me know
Not really. I’d personally do it on the command line, but you don’t seem super comfortable with that sort of thing. @zompel 's suggestion of gparted is a good starting point.
Should I choose Gparted, a PC-98, or something else? There are so many options.
first format in GPT , you can choose ext4 or btrfs.
17.408×1024=17.825.792 MB When I try to enter that, it won’t accept it in MB
The original intent of this thread seemed to be for Feedback but as it has eveolved it has appeared more and more like a Issues & Assistance topic so its getting moved there.
This thing is going to need to be formatted before use.
The DE (or something else) was prompting correctly, especially if you do not already have some data on the disks.
I will allow one ofthe other filesystems experts continue helping with that though. 
Thanks for trying to find something that will help me with this—that’s really great of you.