I need some advice for my first real mesh project

I have an idea that's probably too ambitious for a first mesh, but it's something I really want in my game, and I figure it's so specific that I can't really wait for someone to make it, since it likely won't happen. So I figure I have to make it. I've never done a real mesh. I've messed around with EA hairs and done a really bad job, but nothing more than that. I can't really figure out how to sculpt in blender properly. What I'm wanting to make is a tail like this (though it doesn't have to be this long)  I know I'm probably being idiotic even considering trying to do this for a first mesh, but I'd really like to see if I can try. I just need a lot of advice, since I don't even know where to start. I know mermaid tails are possible, since there are already ones online, so I'm guessing this would be possible. I would ideally like to make it into an item that goes in the tights category, so it could use skirts, but I'm not sure if that's reasonable or not. I know I don't have any very specific questions, but that's because I don't really know where to even begin because I'm completely new to this. I make textures sometimes, but meshes seem so much more difficult. Do you guys know how I could even begin to start on this project? I need all the advice I can get.