Fiance Visa (K-1 visa): Once the fiance arrives in the USA, what to do before getting married?

Fiance Visa (K-1 visa): Once the fiance arrives in the USA, do you need to go to a courthouse before getting married? Or do all the doents given after the interview give you the doents needed for marriage? Like all the doents for my spouse and I to sign and pastor to sign? Thanks in advanced.