I wish I could build like this
I've never really been particularly amazing at building and I'm totally incapable of doing most things artistic. The reason I've been able to make things that are halfway decent is determination with a whole lot of trail and error. The great thing about Minecraft is that you really don't need technical skill to get started with building. You are just as capable of making something worthwhile as anyone else if you put in the time. Like anything, you learn what works and you can just grow from there.
When you have a theme (I've struggled with this a lot), you just start with your basic building block, like a section of grass path and say hey ill make a loop because that looks good in sonic. You add a path either side and since my friend really wanted to add slime blocks, we make a way up to the jump and put that where it seems to fit for the moment. For this map, I didn't know how I wanted the gameplay to work or what shape it would be until I just added things. It came together because I made sure I was consistent in my design. The thing was boring looking until we just stick some detail on top and were sure to add it everywhere that looked even slightly plain.
If you have friends that could give you support, ask them. Another set of eyes will make all the difference. I've found that I can construct a unique design but no way I can do organics, so do what you feel like you do best and if you want to make something, then have a go. There's a chance you will be proud of yourself by the end of it.