Starting to work in After Effects

So I started working in after effects the last few days. I watched almost all of the tutorials, but I still feel overwhelmed. Right now I am trying to animate my tree branch growing, which is not working out as I planned. After Effects unfortunately doesn't have very many paintbrush types, so my branches look very unrealistic, but I think the clean lines may be better for Kill Bills tone. I am also very bad at using the brush tool and my hand goes all crazy. I am using the duration write on effect that records what I do and how fast, but I am just not good at reenacting a realistic betrayal of a tree growing. Hopefully this will work out.