One thing you can do to troubleshoot your Mac is to interact with some things in your Home Library Folder. You can really mess some stuff up in there, so you have to be careful. But, some troubleshooting can be performed in your Home Library. If you plan on doing any amount of troubleshooting in your Home Library, then it is a good idea to have it showing in the Finder sidebar. By Default, the Home Library Folder is hidden. If you would like to have your Home Library Folder showing, then read this article which explains how to do it.