mysql

If you’re going to run WP, you’ll need a web server with PHP extensions as well. If you want something super simple, I’d suggest MAMP:

http://www.mamp.info/en/

That a single install that provides Apache (web server) with PHP extensions, plus MySQL, with a nice little GUI for administration.

You can of course install as separate packages, but that’s more for custom configurations, special needs, etc.

Get that up and running, download WP, drop it in the root directory (as configured through the MAMP UI), and you’ll be pretty close

 

I prefer MacPorts for installing MySQL, since I get always a recent version, while it's installed in a safe and accessible location.

If you installed it through MacPorts, there's a script that creates the initial databases and passwords (if I remember well):

/opt/local/lib/mysql55/bin/mysql_install_db

For starting the server, I simply do a:
sudo /opt/local/lib/mysql55/bin/mysqld_safe &

Of course, I use it just for developing and testing purposes, so you'd probably want a more specific configuration when exposing it to the internet.