Use fusion 360 or any CAD software to design a rover frame , a basic car body 

with essential mounts mounts for the flight controller , 4 motors and a 3.7 v batttery between 250 to 600 Mah.

Print out this file with proper infill and material , preferably PLA or ABS.

the frame should be approximately 200*100*50

Assemble the motors and flight controller with damper onto the rover chassis

and fasten the battery.

Connect the wires of the motor with correct polarity into the motor drivers on the flight controller.  Use the 4 inner motor driver with H bridge support for bidirectional current flow.

Find suitable tyres to fit , onto the motor shaft. One with good traction and approximately 40mm diameter.

Flash the flight controller with the rover codes I created which is on Github.

Use the Pluto App available on IOS and Android App stores  for flashing and driving the rover.