Looking for a PHP security expert

I am new to PHP security and I want to improve the security of my site. I need someone who can teach me the basics and show me how to make my website secure. I already have a website and I have developed it myself but I am not good with security. I have built the site using PHP and MySQL. I want you to show me what is wrong with my website and teach me how to fix it. It's important that you understand that.