The following video shows a demonstration of a kipping pull-up:
To do a pullup, find something to hang from, ideally a pullup bar or gymnastic rings. Hang from the bar with your elbows fully extended but your lats tight. Lats are the big muscles on the sides of your back below your armpits. Now, pull your chin up over the bar. If it helps to jerk or swing your way up (called a kip) as shown in the video, go for it.