You don't need to know how to use all the features of an array to use them. All arrays do is store multiple values in them, and all you need to be able to do is set the size, set values, and get values.
Arrays indexes are 0 based, which means to access the first element of an array the expression would be Array.At(0), and the second would be Array.At(1), and so on...
If you ever try to set a value in a cell that doesn't exist it will do nothing, and if you try to get a value from a cell that doesn't exist you'll get 0.
And as noted above a way you can do what you're asking in your OP will look like this:
So just literally changing a number variable to access different cells.
The push action just increases the size of the array by 1 and places a value in the new cell. Array.CurValue, CurX, etc... are used when you use the "for each element" condition. You really don't really need to use those things. You could use normal event loops with loopindex as well. Overall arrays tend to be more closely related to traditional programming and is more abstract sometimes to understand them.