List view rearrangement using variables not moving or saving

I am writing a screen where I have a list view (with items A, B, C, D, E, F, G) and two buttons (up and down). By selecting an item on the list, I want to be able to move it up and down the list and then save its position on the list so that when I return to this screen on the app, I can see the arrangement I created last time. I am using each variable (method 1-7) to save each of the items on the list. However, my list always appears in the emulator as all 0s and all the items do not move.

How do I get my list to rearrange using these variables? Or perhaps there is an easier way to do this?
The important thing is that the list needs to save and I need to be able to extract the order of the items in the list (each will correspond with a different screen in my app, so later I will have to code to have the order of the items be the order in which these screens appear).

I am new to MIT App Inventor, so I apologize for not knowing some basic features. Thank you in advance for your help!!

These three tutorials might help you understand what you need to do to shift the order of items in your List

Why not just order the items in the List in the order the Screens require them?

Thank you for the tutorials, I will look at them.
The screen are not ordered in the order of the list because the user may choose to order the list differently.

This sample has rearrangement buttons.

Thank you! This was really helpful for the rearrangement feature of my list.