You go to the trainstation, and tell the Monkey you want to invite guests. He'll ask if it's close by (local) or faraway (internet). It's pretty self explanatory. The sign next to him has more explanation about inviting and visiting.A few questions.
How do you open your gate?
How does fruit trading go? Do you just invite someone, they bring fruit, and you let them have at it with your trees?
When someone enters your town you'll be notified. Just make sure you got each others friend codes.
On fruit trading, whatever you prefer I guess. Before, someone was going to visit to get some apples, so for convenience I picked a few and put them on the ground right outside of the trainstation, but you can also allow people to pick them themselves. Just depends on what you prefer, either works.