Ehy guys,it's been 2 days since a elder dragon keeps flying around Dawnstar,even waiting like 10 mins he won't still GTFO.If i go through he will fight me,but since he is elder he will do massive damage to npcs,and i don't want anyone to die.Any tips?(Pardon the language but i'm pissed)

Wait till nightfall (middle of the night) and then engage him..... HOPEfully.... most, if not all the "important" npcs will be inside asleep so it will help keep casualties to a minimum, maybe a few guards... other than that... kill it quickly

Have you tried running away from Dawnstar to get far enough from the dragon to fast travel? I'd try that, then fast traveling to somewhere, mess around for a bit and then fast travel back to Dawnstar. That may cause Mr. Elder to lose interest and split.