one of my quests i was working i had to find someone and when i got where the quest marker was i started talking to the person i had to find and a dragon showed up and he ran off. i killed the dragon and started looking for him but my quest marker is gone and now i cant finish the quest cuz the person i had to find disappered (quest is finding the hunting party)

Um? Quest name or name of person. Anything more you can tell us to help you.

Regardless you should be able to wait a few days or just reload the game and the person should be back where they are meant to be. We just don't know until we know the quest you are on, it can be a simple fix or a quest breaking bug.

Not a good sign if the quest marker is gone. I would search around for his body.

Your being quite vauge

he was sitting on a log in front of me and ran around a bend and hid behind i rock that was where i last saw him then i ran down a hill to kill the dragon and when i came back he just disappeared when i came back i look all over the area for a body but its gone and he quest marker disappeard when the dragon showed up

Have you tried looking inside the dragon?
(Try round about where it's belly was)

Check your quest log/list...make sure that you still have that quest active as your selected quest, if/once you do, then hit the search map function for the quest.

If you want to give specific details then the hints, cheats, spoilers area is, I think, the place for this kind of question.

But in the meantime I would suggest loading a previous save. Otherwise, the only thing you can do is wait and hope.