I’m pretty good with Excel, and you can be too. A little effort is all that is needed to realize your boss’ vision, get that huge promotion and retire in your 40’s.
Type “excel tutorial” into the Google and you will find many, many resources suitable for all skill levels. I will second the general recommendation of youtube tutorials. People have put a lot of effort into making this content and putting it out there for free.
Microsoft has also done a good job with the in-software help, which is always just a press of the F1 key away.
I think Excel is excellent software if you understand its strengths and limitations. I support complex business software for a living, and even though companies spend millions and millions on these sophisticated programs and they have remarkable capabilities, an argument can be made that contemporary businesses are equally dependent on Excel.
Spending some time learning it will be time well spent. Good luck!