For a first effort, this is looking pretty good.

A few thoughts:
- Your rivers are really faint and hard to see. I would make them much thicker and darker, and perhaps add some shadow along them so that they look like they're forming valleys.
- The relief texture is also pretty subtle, so you have to look carefully to see which areas are mountains.
- Your continental shelf seems to be the exact same distance from the shore everywhere on the map. That would be pretty unrealistic in the real world. You would expect some areas with a wide shelf, and others with practically no shelf. Also, I think having the continental shelf effect in the lakes looks weird. Lake bottoms don't usually do that shallow edge then sudden drop kind of thing.

Good luck!