Not to be snarky but, Just start. Pretty much every excel user is self taught. You can google for the name of the formula that is helpful for your use just like you would programming.

Most of what separates a power user from an average joe is having an approach to the problem and laying the foundation in a way to be a “model”.

I’m seen as a power user even within my peer group of finance folks. I just have a way of laying things out and breaking up the problem from data/inputs to print ready outputs. I’m not usually doing anything fancy like using obscure formulas. But when I do, I like these;

* Use -- to convert Boolean to integer * Use index/match instead of vlookup (you can more easily insert/delete columns without breaking) * make yourself a style guide (so you know what a color means; hard value, input, etc) * avoid volatile functions. Learn what functions are volatile * get good at auditing formulas/debugging. It's really just takes experience

Not quite what you want but try this anyway. "You suck at Excel" by Joel Spolsky

https://www.youtube.com/watch?v=0nbkaYsR94c

You can look at a few of the sheets people link to here and just fiddle around with changing things too to see what happens