A couple of good points:
-You used a fog! For a "first terrain" it's not common.
-You used the raise tool, not blizzard cliffs.
A few bad points:
-Background looks like a salt desert. Add hills, or some structure. Maybe a castle using custom models.
-No tile variation. You need to use all the tiles at your disposal. Use grass, dark grass, and some grassy dirt. For your road, try using some grassy dirt around the edges here and there. That way it looks used, like the grass was trampled.
-Ugly trees. I have used them in my terrains, but Blizzard trees are ugly. I suggest using imports. Or just the Ultimate Terraining Map. UTM.
-People. Not always do people ruin terrain, but usually they do.
-Poor use of doodads. Not too bad, half decent, but you need even more doodads. And you could place them better.