tl;dr: reordering stuff in widget containers is a royal pain in the butt
I don’t know how to speak to 5 year olds but I often talk to The Rubber Duck:
- have a Vertical Box or Horizontal Box (or a Wrap Box if it’s more than 1 row / column), this container will host the interactive Item widgets
- ensure you’re familiar with the fundamentals of
Drag & Drop(covered extensively, luckily!) and have each Item implement it
- a vertical box is like an array, its children are ordered
Only with blueprints.
You can Add an item to the end of a VB, you can Get any elementy by Index, and you can Remove any element at index.
However, BPs do not allow Inserting at index into widget containers. You will need a helper array and order it all there first, and only then (re)populate the widget container. This applies only to inserting, other operations would be fine.
- when Items are added to the VB, feed them the Index they’re sitting at
- use drag & drop to reorder the list
- newly added Items go to the end of the VB
- when a widget is dropped onto another:
– store a reference to the item you’re dropping, remove it from the VB, store the reference to the item you’re dropping on
– fetch all Items from the VB and set them to the (cleared) Temp array
– find the dropped on Item and insert the dropped Item at its index; the array will indexes shift by 1
– clear the VB and repopulate it from the array, feed widgets new indexes in the very same loop
– clean up - clear references and the temp array
triggered one by one based on order of placement?
This one is easy providing we ordered Items correctly using the above pseudo-logic. You did not specify what triggers them, I’ll assume it’s on a timer.
- create a looped timer firing every X seconds
- when the timer’s event executes get element 0 from the parent container - that’s the 1st Item
– if these are instances of the single widget class, Cast → execute what is needed, remove from parent
– if the container hosts various classes, consider implementing a blueprint interface to communicate what triggered means; or use inheritance - although inheritance in widgets is somewhat counterintuitive the way it’s implemented…
Explain like I’m 5 please.
You can also use a List View but it’s more involved. These make sense if you have a huge number of items. But you’d need to be, like, at least 6 for that 
Here’s an example of inserting with a List / Tile View:
Now, I did it all in my head, so there’s bound to be a gotcha somewhere there.