Nice! Its near the world spawn so you usually spawn near that or the boat

I'm not sure what you mean, There isn't a stronghold there, however you can leave the map area after swimming away for a while, as it was made in world painter. I left generating structures on so you should be able to find some strongholds when you leave the map's boundaries. If you mean story-wise, then no, there is no ending. However there are 7 secrets scattered across the island (Hint: One of them is near the boat). Hope this helps!