This is quite a good map for your first one, but there are some mistakes that you could correct. One is the amount of grass you have. I find that more oasis would be helpful, because although you seem to have enough oasis to create an economy without much trouble, there are holes in the grass that make it hard to place farms, and there are only a few, if any, places for cow or apple farms.
The map is designed quite well, the only flaw the oasis. The fords around the island are good, and you added ruins. The stone and iron were well placed, and you will probably become a good map maker if you keep practicing. The map is quite creative, the only other map similar to it is probably Cathe: Dark Water.
You don't have any story, so you get a low mark for it.
A harder map that is probably better for experienced players. But a very good map for a first!