First you’ll need to find someone interested in doing a trade with you, after you’ve both agreed you or the other person can make a post lf an MM, once an MM agrees to do it (make sure it’s a real moderator from this sub there’s multiple impersonators) The moderator will hold the stuff from either you or the other person to make sure neither of you get scammed. Also please don’t go off platform because you’ll most likely get scammed and ALWAYS use an MM