Designing herb spirals on autocad

Hello, I'm a university student and i'm working on my final year project. I decided to add herb spiral to the already exisiting permaculture area in my university's campus but i was told i need to draw an autocad representation of my project in 2d and 3d but I'm not well versed in autocad so if can anyone give me predrawn 2d and 3d model or at least tell me a source from were i can download them i'd be grateful