You have to be ordained a minister. Look in your community for non-denominational churces and see what it takes to become certified. You can also be a captain of a boat or a notary to perform marriages.
A Justice of the peace, Clerk of court, Notary or an ordained minister can all perform legal weddings. Check with your particular state as some rules for this can change.
Yes, assuming he's authorized to perform wedding generally in that location, otherwise no. In other words: if a girl's father happens to be a minister who can perform weddings, then he can perform...