Setting up arrow key focus navigation for a uniform grid panel

Hi,
I am a total beginner and am having trouble trying to set this up.
What I want to achieve is so that the player can navigate with arrow keys and hit enter when the desired button is selected.
I tried making 2 integer variables “Currentrow” and “CurrentColumn” but am having trouble setting up an array and dont really know where to go from here. If someone has experience with this, help would be much appreciated. Thank you
Kind regards