very well done for a first map. i would recommend adding in more detail though in terms of water design. try switching between the smallest tile set with rocks/sea (for foam at lowest level)/land then go over the area with smallest river tool and put grass around the water. i usually place it by just clicking randomly around the deeper oasis grass with less thick shrub then proceed to click around the grass with stones or something to make it look naturally faded into the landscape. also, the water going into the ocean needs something more.. try putting in some beach and shrub and rocks and foam. it will look more natural!