hi! so first, you have to have a tpc (town pass card) with a picture, which you can take in the photo booth in town. after you have added someone's fc and they have added you back (so it's mutual), you can visit each other.
if you want to visit their town, have them open their gates. once they're open, you can talk to the monkey in your train station- he'll ask if you want to visit or invite. since you're visiting, click visit, and then select faraway (nearby just means if someone in your physical vicinity is playing and has their gates open, you can visit them, but nobody really uses that feature). then, a list of all of your friends who have their gates open will appear and you can select your specific friend.
now, if you're hosting, talk to the monkey in the train station and this time select "invite." select "faraway" again, and the monkey should open your train station gates for you. then, you can head back outside of your station, notify your soon-to-be guest that you're open, and they can visit your town.
hope that helps!!
