Whenever I open a file Acrobat DC, print screen pop-ups

This is usually caused by a script that's embedded in the file. Are all of these files from the same source?

You can verify if that's the case by disabling JavaScript (via Edit - Preferences - JavaScript) and then open them.

If the Print dialog no longer appears then it was indeed a script. You can try to remove it, if you wish.

It's most likely a doc-level script, which you can find via Tools - JavaScript - Document JavaScripts.

Look for a line that looks like this:

this.print();

or just:

print();

And add "//" (without the quotes) before it. Then save the file, close it and re-open to check if it solved the problem.