At the moment, it is only possible to view and edit references that are stored in a group in Zotero.
After you login to Citesphere, you should see a list of all the groups that you are part of. Clicking on a group will show you the groups contents.
Clicking on a reference which bring you to the details of that entry.
Clicking on the edit icon in the left upper corner, will allow you to edit an entry.