Okay, there's go my opinion:
The map isn't bad, but I don't imagine it in Cubecraft server, the map should be more realist, that mean, instead of the fences (as a object) you need try to do it the most realistic possible (with multiple materials, wood, brown clay etc) I'm not builder, but it's a helpful advice, when I started to build I did the same error that you. To improve a great level of build, I recommend you to see videos from professional minecraft builders.
But please, don't be discouraged, that's not means that in a future you'll not be a great builder. I'm sure that if you'll keep building you can get important things.