Disagreements aren't necessarily bad. Couples that never argue are often in pretty boring relationships.
Whatever the area of conflict, though, resolving the inevitable disagreements in relationships requires effective communicating. Communication is a skill, and skills can be developed.
If you are good at verbal interaction with your partner, you may have learned it from watching your family of origin handle disagreements in healthy ways.
If your family didn't handle this sort of thing effectively when you were young, however, you may find that communication is a frustrating or difficult experience for you. Did you ever watch someone try