PHPStorm can be tricky to setup at first. I can’t remember, but PHPStorm doesn’t recognize local directories for some reason. What I mean it thinks it an error; however, to be sure we need to see the code as benanamen already stated. Once you get that resolved then PHPStorm will really shine.
Some warnings are basically meaningless when it comes to running the code and they can easy be fixed as there is an problems window that you simply hover over the warning click on it and it will give suggestions on how to fix it. Errors can be fixed that way, but my only suggestion is to make sure you jot the original code down first in case the suggestion doesn’t fix the error. I learn the hard way that you can really mess up PHPStorm if you don’t.