Cant add to library on mac

I know i have to be missing something, I've searched for the last 3.5 hours. when i try to add anything to the library, everything is unclickable. it does not matter the format. please help. also it doesn't appear to auto sync either. my library has nothing in it and can't seem to figure out y?
Thank you,
Josh

ok the only way I've figured out, is to copy the path. is that really the only way on a mac?