If I am in that position then I will make a priority
1. Make SOS signs such as smoke, color, and writing on the beach sand that can be seen from ships or planes that pass around the island.
2. Making shelter from nature, such as a simple hut made with leaves, wood, and tree fronds.
3. Make a wooden boat from a tree trunk that can float to get out of the island.
Maybe for 1 month I will survive with points 1 and 2, but if help still hasn't come I have to move on to point 3.
I know point 3 will be very risky because I will cross a vast ocean. There is a possibility of 2. Survivability of being stranded on another inhabited island, or wandering in the ocean and dying of dehydration.
But I will still take the 3rd point, because if I stay on an empty island forever without any help, I will kill my soul slowly.
Nature is cruel, we must be able to survive even though nature forces us to die.