You are in the correct area its just that some of the articles might be referencing the old v2 interface while you are on the new v3 interface.
We're in the process of making sure all our documentation will reflect the new interface however in the meanwhile you can reference articles on this page.
If stuck on anything let us know and we'll assist further.
How would one access the file manager which is listed under Page Content>Upload files to the Site: http://helpx.adobe.com/content/help/en/business-catalyst/sbo/upload-files-using-file-manag er.html
I don't see any of these "Site Manger" or "File Manager" anywhere on my BC interface dashboard??
Please log into your site admin, go to "My Details" and check the option " Enable online editing (incompatible with Muse)". Enter your password to validate, and then save the changes. Your Site Manager menu will become available. You'll have to repeat this operation for each user & site created with Muse.
You should be aware that all the modification from BC admin will be deleted each time you update your site from Muse.
Hope this helps,