I killed this woman, now guards hate me.
 

https://wiki.project1999.com/Olunea_Miltin

This one right here. How can i restore my faction with freeport militia?

Freeport Militia faction page here. Has links for zones you can kill in and quests you can do to raise/lower faction. Look through and see what seems reasonable for your class/level and have at it.

own it, kill more of them

No one knows because we don't your race is, your class, your other factions you might have jacked up etc.

https://wiki.project1999.com/The_Frikniller_Family

If you can do that one it won't mess up your paladin faction in north FP.

Go to darkside! Learn the back alleys of FP and never worry about guards again!