Store the mission names along the X axis, and everything about the mission in the Y axis.
So the entry will look like
X=0,Y=1 Description of level one
X=0,Y=2 Level 1's .JSON load URL
X=0,Y=3 Last date played
X=0,Y=4 Highest Score
When you add a new level insert on the X axis.
You are basically building a small database in the array.
I've read the array for beginners guide. And think I can candle arrays to a small extent. But there are so many things that confuse me in your events. Care to elaborate for some of them? (I know you have labelled them with is helpful, but I guess I need more help).
For example, what are the functions for? And why do I need to "call" stuff.
And why do I need to destroy the sprites at the end, and then recreate it?
Really want to understand/learn from this rather than copy/pasting your work.