Draw me a roadmap (a general overview of what I need to learn to make this project)

edit

The relevant tutorials are all out there. However, I agree that you have to find your way through all of those. So I'll give a shot about how I'd approach this. (No guarantees I didn't forget anything ;-) And, as I don't know your specific requirements, it'll be very high-level. I recommend to follow-up with specific questions once they arise.)

1. model your car in GAZEBO (I'm assuming, this is what you want to use for simulation: Tutorials (plural, you'll need to walk through quite a lot here). Goal: being able to move the simulated car with remote control (e.g. keyboard or a joystick).
2. Get your car localized. Use fake_localization for this (as suggested by @gvdhoorn ). Goal: having the full tf tree set up
3. set up navigation. you can follow the standard navigation tutorials. If your car has an ackermann-steering, you need to choose an appropriate local planner. I'd suggest the teb_local_planner, but there are probably others that you could use as well. Goal: being able to send the car to a single point (from rviz).
4. Implement a node that creates and services your random points to the navigation using an action client. Goal: full functionality.

I hope this makes sense. Godspeed :-)