Are you talking recreational classes or competitive gymnastics?
Either way... the best way is through experience. Learn as needed as you go. I would just apply for a job and start with whatever training they give you. For example... here is a club that provides a great little curriculum for the coaches to follow...
Get Skills… Get Swag! Now you can see all of the skills that we are teaching in class so you can move up and earn swag!
orange.midwesttwisters.com
One of my personal favorite sites is Al Fong's site...
A platform designed by Al Fong to educate, inspire and help change your culture in the gym by offering coaching tools and philosophies we have used over the last 3 decades to produce gymnasts at all levels.
www.alfong.com
It's a bit difficult to navigate... but once you figure it out... it's great.
As far as the ultimate resource... it's the interweb. From Youtube to following Instagram accounts that you like... it's all out there... except experience... you gotta jump in to get more of that.
https://www.instagram.com/recgympros/
https://www.instagram.com/bestdarngymnastics/