Sri Lankan getting married to an American

Hi all, I'm a Sri Lankan planning to get married to my American fiancé. I'm still confused about the procedure and also applying for visa after the marriage. Would like to get some insights from anyone who has done it before. Is there any time limit for all these to happen? What's the procedure when getting married? Any legal constraints? Let me know everything you guys know please!

Spousal visa
You get married anywhere you like, return to your home country and the US spouse starts the process. See travel.state.gov which is rather easy to navigate.