Newbie: How to start

I am a newbie to ardupilot. Here is what I plan to play with since I do not have any real hardware component/car. 1) Try to run a simulator so I can set up some environment running an autonomous car/cars; 2) Develop some new software program to control an autonomous car in a given environment and finally transfer the code to a real hardware components/car. I check the website: First Time Setup and Configuration — Rover documentation (ardupilot.org) and is the first step what I only need to run the simulator and develop a new program? Thanks.