Computer Science how do i move cars labelled by letters which are in a 2d array grid like below in a specific direction be it up, down, left, right depending on where there are facing. lets say i have...

how do i move cars labelled by letters which are in a 2d array grid like below in a specific direction be it up, down, left, right depending on where there are facing. lets say i have many boards and the program has to find the next letter and determine the direction it should move? am really lost on ho i determine the blank spaces.