Build me a racetrack for the game Assetto Corsa

!!! ATTENTION !!! I know nothing about the pricing, so I may have set the price too low. In this case I think we can talk about a few dollars more if needed, or just igonre it. I want my own racetrack inside Assetto Corsa, but I know nothing about making 3D models. I've looked up how to make one, and the other things aren't too hard, so I can do them myslef, but the modeling part is what holds me back. I'd like to work according to the following tutorial (I'd like you to follow it, so I can work with your work later): [login to view URL] If you're interested, I can send you my plans about the track.