Can someone tell me what should I expect in the USA/Mex border; I got the visa appointment letter, the appointment is set for first week of September, If I travel to the American Consulate the day before the date, how long does it take for me to get access to the USA and what do I need to bring, what should I expect? Thank you for any advice.

If this is your interview then you should bring everything on your checklist, but don;t forget your birth cert, Photos, proof of a relationship, and airplane tikets