Arduino Programming

Hi, I need my Arduino to monitor speed and be able to control the speed of an item, (kinda like cruise control). I have a 12v system with the Arduino Uno, Dual H Bridge stepper motor drive controller board module L298N TG, Lcd 1602 Keypad shield, Arduino hall effect sensor module. The item will be moving very slow, i have a rubber roller which rolls along the ground which has a metal disc attached to the outside and has teeth like edges so the hall effect sensor can read ground speed via the teeth on the roller. Currently there is a lever on the item that you manually move back and forth to control its speed. What i would like to do is use a linear actuator to move the lever back and forth to control the items speed. I would like the Arduino to also have a menu on the lcd screen. On the menu I would like to choose the speed of my item ranging from 15 metres an Hour minimum, up to 70 metres an hour Maximium. So when i choose the speed via the lcd keypad it reads the current speed via the hall effect sensor on the rubber roller and adjusts as necessary using the linear actuator. I would also like displayed on the screen the current speed (in metres per hour), and the current speed setting. Also i would like it to have a counter on it that measures in metres the distance being travelled, that i can reset at anytime by the press of a button, I need this counter as i would like the item to be able to change its speed at certain intervals (in metres), for example, i set it for 20 metres an hour for 50 metres and then change to 30 metres an hour for 100 metres, id like to do this example by resetting the counter, set speed to 20 metres an hour for 50 metres to start at 0 metres, scroll to next option and select 30 metres an hour to start at 50 metres distance. I assume that there will have to be a calibration done so the metres will be read accurately, something like a "pulse per minute" option in the menu that i can change. As a safety feature i have a small LED light that i would like to attach to the item and have it blinking while the item is in motion and the arduino would control this action as well. I believe I have all the right hardware but im open to changing anything that you might think would be more suitable. Can you show me a Wiring Diagram, and the program that i need to upload to my Arduino.