Called Samsung today about my PDF questions. I was passed from level 1>level 2>level 3 tech support. Even the level 3 tech didn't have the answer but was willing to research it and work with me to find a resolution. Here goes:
DELETE PDF FILES:
My Files Folder>Download or External SD card if using SD card then download>Find File>Tap & Hold File Name>Delete>Check file(s) to delete. Can attach phone to PC to delete multiple files easier and quicker.
ATTACH SAVED PDF FILE TO NEW EMAIL:
My File Folder>Download or External SD card (download)>Find File> Tap & Hold>Share>Opens email. Complete email as desired.
Would never have figured this out without the Samsung tech's help. Kudos to John.
Tap Adobe shortcut, tap bars in upper left, there will be a drop down menu , scroll to "documents". Upper right corner says edit. Tap edit , check boxes by items you want to delete. Tap trash can icon in upper center of the screen. You're finished !