Yes, this is definitely an off-topic thread, and I've moved it to the right sub-forum.
PHP is a programming language, often used to write websites. You do NOT need to know PHP in order to use programs written in PHP.
MySQL is a database manager. Programs written in PHP often use MySQL databases. Some programs which use MySQL databases create them for you; some require you create the database yourself.
WordPress is a program written in PHP which uses MySQL. Whether or not it creates its own database depends on how it's installed. You should check with your hosting provider to see if they provide a simple install for WordPress, which will create the database yourself.
If not, you'll need to install WordPress yourself, following the instructions provided at the WordPress download site, and you'll need to create the database as well.
This forum isn't really for teaching you how to create a website using WordPress.
Google is your friend.
Jeff