For something completely free I'd sign up at http://wordpress.com (note that this is quite different from wordpress.org). The commenting system is built in with social media integration as well. The only issue is that the templates and customization are limited so your site could end up looking like...well...just another wordpress site. There's no actual coding required and this is actually one of the largest communities on the internet if you're looking to reach beyond webcomics.
Weebly is another free site builder but there's no commenting system. You can build a nice site and a shop by dragging and dropping page elements but it's quite limited in terms of looks as well.
Then there's self-hosting - which is not as difficult as it seems and you have complete control over everything in your site. In the end, the pricing works out much cheaper than squarespace - which is actually where I'm moving from. I'm setting up a new self-hosted wordpress site using siteground which has a 30 day money back guarantee and great support system to help out. They have a site builder through weebly if you like their templates - I believe it's the commercial version too so there's more options for running a shop. They also use scripts which are literally one click installations and there's tons of documentation to help out on the way.
side note: If you are using self-hosted wordpress you can install all sorts of plugins and themes that are not available on wordpress.com and still integrate with that network using this plugin called jetpack. (ie. your posts will show up in the wordpress reader which has a huge readership)
The cheapest self-hosting option I've found is asmallorange but I found their support to be quite lacking.
No matter which route you take there's always a learning curve to setting things up but nowadays you can build a pretty decent site without coding a single line.
