A message forum for general discussion. Please come and chat with others!
Questions about how to use the site belong in "Technical Support Forum" , which is linked as Need Help? at the upper right, and also as Writing.Com Tools/Help: Technical in the left nav menu.
That said --
Uploading covers requires an Upgraded+ membership, not a Basic.
Regarding using images from other sites, members are not allowed to upload anything that infringes on copyrights. Also, uploading happens from your computer's file manager, not from other sites.
However, anyone can use the stock covers. See Covers from Writing.Com 101 .
Hope that helps.