I'm confused!
Acrobat Reader opens .pdf files, so there doesn't appear to have been any 'conversion' involved anywhere. It appears to me that you simply need to change the way that the program displays your documents. This might help:
https://community.adobe.com/t5/acrobat-reader/how-do-i-remove-the-right-hand-pane-in-reader-dc-locked/td-p/7021654?page=1
It might be far simpler though to switch to a
better PDF viewing program. Although Adobe (which is the firm behind Acrobat Reader) invented the PDF format, their software for working with it is clunky and horrid. It frequently features in lists in tech magazines among the programs that PC users should NEVER have on their machines.
The most popular alternative is Foxit Reader
https://www.foxitsoftware.com/pdf-reader/
which is far, far better than Adobe Reader. However my own preference is to use Sumatra PDF
https://www.sumatrapdfreader.org/free-pdf-reader.html
(Both of those programs are freebies).