This is a wierd one. It is similar to some other posts, but their fix doesn't help. I can open Premiere, but if I try to open a file from the recent projects list, or I use the Open Project option OR I try and open a project directly from Finder, Premiere just locks up. BUT if I open a New Project first, and then Open a project from the File menu, it will open. I have tried holding option while starting, but I don't get a window asking if I want to reset preferences. I've screen captured an image what's happenening in my Activity Monitor if that helps. I'm using the most recent version of Premiere and am up to date on all updates.
If that doesn't work, try resetting the Workspaces: Reset a workspace Reset the current workspace to return to its original, saved layout of panels. 1. Do one of the following: • Click the Workspace menu icon and select Reset to Saved Layout. • Choose Window > Workspace > Reset to Saved Layout. from here: https://helpx.adobe.com/premiere-pro/using/workspaces.html
If that doesn't work, try Preferences > Audio Hardware and set Input to None.