Utility

For any Island to function you must have enough Utilities to support your structures. These utilities give no profit or entertain your tourists, rather they provide a function to support you or your regular structures.

The Administrative building provides staff to operate your structures, including other Utilities;
The Energy Unit production facilities provide energy to power your structures;
The Totem of prosperity and Oracle of Fortification increase the Profitability of your regular structures.
The Business center and Bank generate Piastres for you.

The most important facility is the Administrative building where you reside and do your Administering from. As such it is the only Utility that you already start with and as it cannot be demolished it does not appear in the Utility Build menu.
Your Main Pier is where your tourists arrive on your island by boat, and after repairing it initially in the tutorial, it is generally not interacted with directly other than ensuring you maintain a road from the pier to the Administrative building.
You Second Pier is broken and once you get to the stage where you can repair it, it becomes an Atlass Hotel with its own helipad. See the Atlass Hotel page for its unique properties, which also cannot be built from the Build menu.