Disallow PHP Execution and can't locate the wp-config.php file??

Hi!

I purchased the GP Premium plugin because the other three plugins didn't work anymore and I've always been able to find the stylesheet and all that, but now I can't find it. Am I just blind or have I messed something up? To get rid off the "Disallow PHP Execution" I need access to the wp-config but as of now my brain is completely blank. What do I do? I think I need a better explanation :(

Sincerely,
Lisa