What you are looking for is exactly what GEDCOMpare is intended to do. You've finished reviewing your suggested matches, so you should be seeing little "ADD" buttons next to the rows for people who aren't already in WikiTree. You can ADD those people to WikiTree by clicking on the ADD button to get to a screen where you can load your GEDCOM data for the person into a Wikitree Add Person form, review the form and tidy up the bits that aren't the way you want them to be (GEDCOM imports sometimes contain ugly computer-formatted junk), then create the profile.
I suggest that folks working through GEDCOMpare should start with a profile that is in both WikiTree and your GEDCOM, open a "Compare" screen for that person, then work off the compare screen to ADD profiles for people who aren't already in WikiTree. Add parents before adding siblings and add spouses before adding children. Working from a COMPARE screen and adding new profiles in that order helps ensure that the relationships between family members get imported correctly. When you finish with the first Compare screen, open the compare screen for one of the people you just added, and continue...