admin problems with sharepoint

I have a problem with the administration of our company's SharePoint.

I am global admin of the 365 account and I'm trying to add some features to the SharePoint, but I can't find the Site Settings menu item in site actions (even on top of the site collection).

After reading that I had to be Site Collection admin, I went to the admin page and clicked on the "manage" link under the SharePoint section of the page. The problem is that I receive and access denied error.

note: it is still a pre-2013 office 365 account