I have now even tried to create a new account to link to my site, with a new c5 user name email etc. It gives me a welcome message and says "Please tell us more" with the same errors:

You must specify a site name.
Invalid site URL.
Your site token must be 64 characters.

There are no links, forms or anything else that I can see on the page. I am absolutely frustrated. Can anyone give me an idea of what I am doing wrong, because this is insane.

You must already have a project name S_S_title from the same site. The default name for sites that havent been named yet, and when trying to add a second unnamed site from the same url (website address) theres a problem because they are both named S_S_title, and same url.

Go to your dashboard, click system and settings and in the first column marked basic click "site name" give it a name. Now connect to the community and you should be good. You can also delete the old project you have connected to that address. I think you should be okay after that.

I have changed the site name and when I attempt to follow the install instructions I still get the "You have not connected any sites to the concrete5 community." message on my projects page.

I have the same problem, what can I do?

Here's a guide for troubleshooting problems connecting to the community:
http://www.concrete5.org/documentation/how-tos/editors/cant-connect...

Here's a video about how to connect your site to the community:
http://www.concrete5.org/marketplace/how_to_install_add_ons_and_the...