Anyone using A Lumia and gophone?

So I bought this Lumia 620 and want to use it with a gophone sim. I'm new to WP8 and wondered if there are any tricks to unlocking setting APN etc. Basically I'm a noob in the WP8 world and need a chaperone. I know how to do all of this in Android and iOs but I'm a stranger in a strange land when it comes to Windows Phone. Any places I should look first for this information?