Taxonomy Term View - how to display parent View term info when child terms exist?
What you would probably want to do is create a view of the taxonomy terms that lists Parties, Sports, etc.  On the fields to display, re-write the output to a link to categories/%1, which will take the term being listed as an argument, and make sure to un-check link to taxonomy page.  For this view you should make the link something like "categories".  Then, in the second view (or maybe just another page in the same view), make the link something like "categories/%"  The % wildcard will take in the value of the taxonomy term form the page before.  So when you click the link from the first page it will link you to the second view, where you can make a contextual filter that takes the taxonomy term given via the URL from the one clicked on the first page and have it list the terms based on that with a relationship.