Well this video was made before they added skull island, where the hourglass is. Anyway, I'll answer for anyone watching this or reading this: If you look at the hourglass, it contains liquid which will slowly pour our every day. Pay it 8 coins to "freeze" it. You lose skull island if the liquid (time) runs out. I think it lasts 50 days if you never freeze it. Oh and the freeze for 8 coins only lasts one day. Then you have to pay 8 coins again to freeze for another day.
Probably because you're on the first island. You gotta use the ship to travel to another island and there you will find shrines. Beware tho because if you travel on the island you start over back to square one.
Niam Nizam go to the very end of I think the left side of your island (if it's not the left it's the right) and pay 10 coins once your by your boat to set sail
