What kind of connector do I need to connect our outside tap
The normal pipe fitting at a bib is 3/4” inch here in the U.S.
So you would want a female but that looks like a hose fitting that requires a o ring or washer to seal. The outside one would use “poly” hose that slips into the opening and locks in place but I can’t even give a guess on the size from the photo. This is a bit of a hack setup although it may work I would want proper plumbing here especially going through a wall.