This looks like an prime settlement location, walled, plenty of turrets and nice houses inside.

However I rescued the girl in the quest, all people turned hostile to me then I returned far later.

I killed them all and took over however the beds are owned same with most other items.

Is it an way to fix this?

Covenant is curently buged, only way to fix it is by using console commands(so eather do that at your own risk or wait for a patch that fixes the settlemnt)

yeah, you CAN kill everyone, it's one option when you do the Covenant Quest. Current problems: 1- the turrets don't count towards defence, you have to destroy them and make new ones 2- the house contents are red, but you can get around that by recycling them. 3- Deezer, while happily serving you lemonade, doesn't like you touching anything 4) you can't recycle/change/build outside the gates. Hopefully a quick mod or Beth bug-fix can fix these issues. It is one of the best settlements in the game (Fiddlers Green trailer park being the other, but you can't build there as there is no workbench - YET)

yes, do not like to scrap the nice beds.

Well I am on the play station 4 first off so theres that..... In general with much cursing and trail and error I have learned.

In Covenant the bed owned issue can be solved simple enough by assigning a settler to it (you do need to build a beacon and power but still, just use that same first settler that shows up on all the beds) I still have a dikeens of a time moving the beds so I just leave them there. You do need to pretty much scrap or steal all the items just to avoid causing a later accidental village slaughter. The cat and the bot are both spies and hate this, do it when there not around.(hack the bot is really nice for this to put in sleep mode) The house doors well just have to go sadly locks on them grr. The turrets can be moved as they do not add any to defense, and I hate the clutter the leave when you take them out in retrospect building a stairway to avoid the main doors and taking them out back to add permanent burning torch's might be clever, . Ya the main doors svcks your stuck with them unless you do stairs.

Also in general before you access any work bench clean up your mess , move any bodies you are able out of the area this trick has kept those nasty all ready dead corpses at some places, plus ones you add from cluttering up the place if you take this step before you tag the bench. (this really cleaned up a few areas enough for a start over heheh)

Thats all I have but it actually may be helpful

"saving the girl" isn't a good thing from the point of view of people in the town, she is a synth and the townpeople are totally anti synth, you have to let them kill her in order for them not to be hostile toward you.

Not the point, it's bugged either way you do it. And killing them all is just as viable of an option to take over the settlement.