One nice feature on Mac is that you can select text anywhere, right-click and choose Services, then if it is a valid path you can select Show in Finder. Try that on this line:
That is the right PLIST file to delete. Make sure to have closed SketchUp first.
I was on a screen share with someone a few days ago, who was having the crashing issue. I had hoped to test the PLIST deleting idea, but it turned out that SketchUp was being run from within the wrong folder, and the folder was also set to be invisible. When I put things into the right location (meaning, a visible SketchUp 2021 folder inside Applications), we couldn’t make the crashing issue happen. So I wasn’t able to do the PLIST test.