Took me a bit but I got it. The break through was noticing that clicking the boxes opened up my inventory and I could order items through there.
It is easy to find things in retrospect that should have been added or left out. I think it can be easy as a developer to forget that new players don't know what you know. I remember the first tactics game I played. I didn't know I could select different party members by pressing R & L. I played the first five or so missions with only one character and a 'guest' character. Eventually, I felt I was missing something because I could find more people than I could deploy in the equipment menu.
I think I eventually searched the manual and found a tip on how to select different people. It was long enough ago I don't really remember how I found the answer to my problem, but I did have to look it up.
I guess that is the value of doing little projects like this. You can quickly learn developer lessons.