Alright, the dock is pretty good. I'm not sure you did it though seeing as your trees don't have textures. As a whole, it looks pretty good. I would consider experimenting with Roblox parts before Smooth Terrain. There are guides online that show how to make islands, volcanos, etc. I would consider you look into watching some of those. If you don't already have it, F3X is a great tool for creating with Roblox parts.
https://www.roblox.com/groups/group.aspx?gid=2622473
^ This is for learning how to use F3X. There are YouTube videos explaining more as well.
If you need help just message me.
The only diffrence bettwen SBS and F3X is F3X has more increament options as well as keybinded hotkeys you can use SBS its just not as productive and takes alot longer to build with