My current URL is below. I'm using a custom php function to pass three GET variables to the page "world":
How can I make my URL look like this?
Some googling points me towards the .htaccess file but none of the tips are specific to my goal and I haven't worked much with htaccess.
Generally URL rewriting being done by adding url rewriting rules in .htaccess file. Wordpress have a builtin functionality name Permalink to do it.
In Wordpress admin go to Settings → Permalinks panel (Options → Permalinks before WordPress 2.5), you can choose one of the "common" structures or enter your own in the "Custom structure" field using the structure tags for defining your choose of URL. You can also find plenty of plugins for url rewriting in wordpress like: