Here are the simple facts - society, through its government, ALREADY regulates marriage.
You have to be a certain age, (with parental consent, even older without it).
You have to be married to someone legally of the opposite gender.
You have to be unmarried at the time you get married.
Can't have multiple wives or husbands, can't marry animals, can't marry close relatives, can;t marry dead people.
If you want to CHANGE this, CHANGE society.
But you haven't yet....