Are you like 12 ft. tall or something?? LOL Your photos look like you're towering over everybody. edit - Wait a minute - were you on the back of a pickup truck or something?? If so nm...
Anyway, you seem to frame high sometimes, I'd include their feet and not so much background. Most of these are nice group shots, just watch like in #3 so you don't get half a girl (right side) and more space than you need to the left (frame either more to the right or left, if you want the girl to the right included or out of the picture). The picture seems to be about the couple in the middle so I might have flipped the camera and framed it vertically instead (to minimize people in the background to the left and the girl in the foreground to the right). Some of these might benefit from some cropping.
It takes practice I think to get good at split second decisions as things are happening. (edit - I suggested trying different vantage points, but if you were ahead of them in a moving vehicle, never mind. lol if you were on foot, you could anticipate the next group coming and stand so you get them coming your way but not always straight on.).
Keep at it and keep practicing.