SERIES PREMIERE: In the hands of anyone but executive producer Ellen DeGeneres, the concept of First Dates would be in danger of being swallowed up by a mean-spirited reality-show riptide. Not so with her in charge, so, with this new real-life look at first dates (narrated by Drew Barrymore), expect something with elements of humor, intended to be heartwarming and ultimately life-affirming. If, grumbles Ebenezer Scrooge, you enjoy that sort of thing…