I have read that if two parents can't agree on a babies last name that it will be hyphenated by alphabetical order in the state of Florida. Is that true?
absolutely NOT! If you two can not agree on a last name, in order to prevent having to do a name change later in life, you can hyphenate at birth and that whole name will be the child's last name. It appears that when people get married these days they think that by hyphenating their last name it gives them legal status. It does not, they must file a name change in order to effect their new last name.
If married the child takes the surname of the father, if not then the court decides, what you "read" is inaccurate.