Welcome to the Guild! Good job on your first map!
I'd add a few hills around the mountains. You also need a few rivers-- they'll come down from the mountains towards the sea (and some will probably go toward the lakes, unless you want them to dry up soon). You can read more about placing rivers in the Tutorials section, or just click here.
Welcome to the boards
I would add a border around the islands the same shade as your lake just to give it a little more definition. The small outer islands kind of blend into the background. Looks good! Like the old paper look for the background.
I followed advice of Aminowrino: I have to add hills, and river, I did not well understand the tutorial about placing rivers I thus put them a little bit at random. Here is new version there:
Miinstrel, I am not sure to understand that you wants to say to me. islands, the big as the little have borders, although those of the big are more darkened.