The Bantams had failed to find the net in their three defeats at the start of their League Two campaign but they showed some clinical finishing at Whaddon Road.
They led three times in a bizarre first-half that also saw the home side make all three of their substitutions.
McCall said: "We conceded four goals so, obviously, I'm not happy with that. But I'm delighted with the victory.
"We have a lot to work on, especially with defensive free-kicks. We were so deep when they scored it was criminal. But we are a young side and we have to take the positives out of it.
"There were a lot of good performances and the best thing was that we scored a goal then we scored four more. There were some terrific goals and we have done some hard work on the training ground so it was good that they came off."