She sets out for Galar through the Azure Bay

Serena is an aspiring fashion model of Kalos as well as the current champion. She has recently been asked to go meet a fellow fashion star of the Galar region named Nessa. Unfortunately for Serena since her modeling career hasn't taken off quite yet she doesn't have enough money to fly there by herself so she has to come up with some other way to get there. She remembers travelling north of Coumarine City at some point and found some strange place of islands and such and tons of water. Apparently it's called the Azure Bay and it's also the route she needs to get from Kalos to Galar. She lets her friends and mom know where she's going and they hope for a safe trip there and back. She heads over to the Coumarine docks, sends out her surfing Pokemon, the Lapras she got from random guy shortly after beating Korrina and getting her Mega Ring, and heads out into the great unknown.