I'm assuming you're asking how to trigger these in game?
Look at the achievements section for each girl in your phone. If you hover your mouse over the images you'll get a hint of where a scene takes place. In addition, the scenes are grouped by location. If you see a question mark by a gym scene, odds are it's also a gym scene.
A girl's arrival is a type of event. After you've invited a girl to the island by speaking to the receptionist, you'll have to wait until the next day when she gets there.
To trigger, travel to or from your room. If nothing happens, let half an hour pass, and try again. This is also a way to trigger girl's shower scenes. But arrivals are easy to trigger. As long as you go back to your room at some point after inviting a girl, they'll activate.