The absolute best way to learn what arrays do and how to use em is to open up some kinda spreadsheet and start setting values. Each cell on the spreadsheet relates exactly to a location in the array.
A 1d array = a spreadsheet with just 1 column but however many rows you want
a 2d array = a spreadsheet with 2 columns and however many rows.
a 3d array = a spreadsheet with 3 columns and however many rows.
It really is that simple. Try to work with an array in c2 and at the same time have a spreadsheet open and use the spreadsheet to input your values you want in your array then you can use the exact locations of the cells to know where that value should be in your array