Remove categories list.

Looks like you have a secondary menu set up. Try going to Appearances -> Menus in the admin panel. There should be tabs on the right with the names of the menus on your site. Select “Secondary” and delete it. Hope that works.

That theme is not released under the GPL license which is not in keeping with WP policy and philosophy – and it thus not supported here. I’d strongly suggest you read this and find another theme that is of known good quality and complies with WP policy.