Squid Coast is Tutorial area and there are 2 chests and 2 secrets to collect here. Video is at the bottom of the page if the written guide is not clear enough.
Chest 1
From the starting location instead of going straight ahead, turn right and jump to cross the water to reach to the chest
Secret 1
From the location shown in the picture below, enter a narrow path between the bushes to reach the lawn in front of the house. Secret will be revealed as you get there.
Secret 2
From the location shown in the picture below, enter a narrow path between the bushes to reach the lawn in front of the house. Secret will be revealed as you get there.
Chest 2
This chest is on the main path and is hard to miss. You’ll have to jump to get to the chest