This can be called a beach, a coast, or a coastline among many other things.
an island
Land along an ocean or sea is called a coastline.
Coastline
cape
'bed' sea bed lake bed
It's on land
There are many names for it. Maybe the beach, the coastline, the coast, or the shore. Note that coast means more the seaward limit of the land, while shore is the landward limit of the sea. Also, shore is a general term for land boardering water, while coast is land directly along a sea or ocean.
At the coast. This is the term for where land meets the sea.
in the ocean
The longest sea in Africa is Indian ocean along side with Somalia.
A beach
A beach
Apollo 11 did land in the sea, which is the Pacific Ocean.