Removing Custom Sorting Option for Guests

[HappySmoking]

In my Moz.com dashbaord I'm getting reports of duplicate content errors for URLs like this: https://www.hookah.org/community/forum/13-hookah-lounge/?page=1&advancedSearchForm=1&sortby=forums_topics.last_post&sortdirection=DESC

These are pages that allow the users to do a custom sort of posts in a thread. Does anyone know how I can do one of the following:

1) Remove the Custom Sorting option from the different sorting options available to Guest Users?

2) Put a canonical tag to not index these pages as separate pages?

[sweethoney]

there is an issue with website skin not showing right theme little when you go to community