It looks like you are signed up with "Family Member" status. There are limitations to what you can do. Family members can "Edit any profile if they are on its trusted list". You have two choices. First, you could sign the "Honor Code" and become a Wiki Genealogist which would let you edit any open profile (and connect your father) or second, you could contact the manager of your father's profile, Hartwell-3730 and ask to be added to your father's trusted list. Either method would let you connect your father but if you are planning on staying and adding to the tree then the first option is the best one.
https://www.wikitree.com/wiki/Help:Membership
