After waking up, examine the mirror to change out of your pyjamas. You can interact with the various objects in your room if you want then once you’re done, you can head downstairs to find your mom. She will then tell you to say hi to your neighbors. Leave the house afterward.
After opening the door, you’ll find two other kids waiting outside. They’ll welcome to Vaniville town and introduce themselves as Serena (for male characters) or Calem (for female characters) and Shauna. They will also tell you that the esteemed professor, Sycamore is looking for five kids, including them.
You’ll see them leave the town through the gates and you’re inclined to follow. You can explore the town as much as you want; when ready, you can leave the town and follow the girls. You can press and hold the B button to run. Go through Route 1 and you’ll reach Aquacorde Town almost instantly.