Moving Multiple Layers on Timeline This is probably a simple question, but I do not think I know the terminology to search for it.

All I want to do is move the start point of multiple layers forward without changing the sequence of them. I've tried all the features I can find to do this, but it always changes the sequence.

The first thing I tried was selecting the layers I wanted to move and then:


Animation >> Keyframe Assistant >> sequence layers
In the dialogue box, I left overlap unchecked and hit ok, this failed to do anything
In the dialogue box again, I checked overlap and tried all of the features, each time it changed the sequence of the layers


Next I tried


Moving the timeline indicators to where I wanted it
Choosing the option + open bracket key 
This only seemed to change one layer, so I just undid it.


All I'm doing is trying to add one simple slide into a slide show and move all the slides after it, but it appears like I'm going to have to sequence every layer again, which is hard to believe that there would not be a simple way of moving everything forward without changing the sequence order.
There are lots of add-ons that help with stacking and layering in the way you describe - try pt_shiftlayers for example:

https://aescripts.com/pt_shiftlayers/