Hi there!
What you need to do is note down which two pages are causing the duplicate META DESCRIPTION and then log into Wordpress and go and edit those posts or pages.
At the bottom of the page editor are boxes for title and meta description, so you will need to change one or both of them and then republish the page.
Let me know if you need screenshots as I have a couple of clients who we use Yoast's SEO plugin as a part of managing the on-site SEO.
Thanks,
Martin
a hosting company should just host and you should be using canonical tags and .htaccess to sort out your own canonical URLs. So my gut reaction is to change hosting company.
You go to some lengths to not register and really, apart from the majority of people not knowing how to do a reverse image search, probably reflects people's attitude to those sorts of lightbox registration forms.