I just discovered Dawnstar, after I arrived some vampires were attacking the city, I helped the guards kill them, but afterwards the guy who owns the Dawnstar Museum attacks me on sight. I just googled and it says is something about a high bounty on the pale. Well, I checked and I have 1030 bounty on the pale, I dont know why because I didnt kill any citizen nor guard, and the guars wont atack me even when it says I got that bounty on my head, I talk to them and there is no option to pay off the bounty.

Is this a bug or what? Is just I dont want to start another game, I crated this one preparing for Deagonborn and Im pretty happy with it after more than 30 hours of effort.

I just tried stealing arrows from a guard to see if when I get caught he charges me the ful price, but he only asked me for 25 gold and to return the stolen items... I dont know what else to do

There is a "hidden bounty" glitch in the game that can cause non-guard NPCs who belong to local law enforcement factions to become hostile because they see a bounty that the guards don't acknowledge. The solution is usually to do what you've already done, commit a small crime in front of a guard and get caught and then agree to pay your bounty to the guard. Typically paying the guard whatever he asks will clear your entire bounty in the hold, even the one that the guards don't seem to know you have. If you have stolen items on you, though, you will lose them when you pay the guard. If you can store your stolen stuff in a container or with a follower before paying the guard, then do so.

At any rate all you can do is pay the guard the 25 gold and see if it works.

I did payed but nothing happened... oh well... I just loaded an older save and didnt go there, instead, I started to play Dragonborm right now... will visit Dawnstar again in some more time, thanx for the adive

Sorry it didn't work. Sometimes just not going there is the best option all the way around.

Have fun with Dragonborn!