If you're not already watching Friendly Cosmonauts stuff, I would start there. I don't think she has a stat tutorial, but she does do both her menus, inventories, and a number of other systems with arrays and she's good at teaching them. Also, she's doing a farming RPG tutorial which is slightly different but does have a number of relevant overlap.
Otherwise, if you want something slightly more complicated, you could probably look up college courses on arrays and similar subjects (on YouTube). They'd be in a different programming language but the array concept is pretty universal and those types of videos often cover a lot more of the nuance than you'd get from a specific do this thing with arrays.
Array Specific:
https://www.youtube.com/playlist?list=PLRqwX-V7Uu6bO9RKxHObluh-aPgrrvb4a
Full Intro Course:
https://www.youtube.com/playlist?list=PL4C4720A6F225E074