If you've finished all the comparisons and matched where appropriate, you should see ADD buttons on the left of the WikiTree Profiles column. You can either add people by clicking the ADD button, or you can go to a profile that you matched with an existing profile, click the COMPARE button, look for family members that have ADD buttons to the left of the MATCH TO and COMPARE WITH buttons, and add them by clicking ADD.
(All this is assuming that you've already been confirmed as a WikiTree Genealogist, which is true in your case; if you hadn't, then you'd need to do that first.)
