new and confused..re:login and plug in key

Just signed up, and can post and change themes, etc, but when i try to activate the anti spam plugin, i am told to “register’ evn though I am already logged into my site. So, I am a little confused..is there a separate registration for logging into the admin panel, then from the panel to get a key? When i follow the trail to get the key, i end up on a screen that asks me to register, and when i put in my user name and password, i get “user name incorrect”..any clue as to what is going on?
thanks,
John