ssh key adding to agent error

I've been trying to learn web development and have been using Atom and Github. In the past few weeks and for some unknown reason Github has twice stopped allowing me to push commits to repositories I created and the error is that I failed verification. Theres a job aid that explains how I need to create a new SSH key on my macbook and add it to the SSH agent. I've verified the path to my RSA folder (users/me/rsa?/id_rsa.pub?) and I dont have trouble generating the new key but when I try to add it to the agent I get this error: Host: couldn't get address for 'Desktop': not found' . I dont understand why the desktop is coming up because I dont have my ssh stored there. The command Im using is "eval $(ssj-agent -s)". ssh-add -l returns a message that "the agent has no identities". Whats going on and how can I add the key to my agent? Ive owned this macbook for about two months and purchased it new from apple.