How to help with package maintenance

Any tips / resources on how to start building rpm packages. Im ages on linux yet never build any package for any system. But I compiled lots of stuff back in the days.
I wanna learn to possibly help in a future with the project. And I have to start somewhere.
Beeing a guy who just run linux and is quite advanced not enough for me anymore.
Im no linux wizard but I know how to manually compile stuff kernel included.
Let me put this that way.
I can help with money which I kinda lack of at the moment or time. And I have to much of a free time. I can waste it for mindless amazon / netflix entertainment or try to learn a new useful skill.

I found this (https://www.youtube.com/watch?v=woFtdIS6x0Q
GitHub - jordansissel/fpm: Effing package management! Build packages for multiple platforms (deb, rpm, etc) with great ease and sanity.
Maximum RPM
RPM Packaging Guide
Is that even good point o start??

Got to start somwhere

Yup I know it will take time to lern the basicks even more time to craft the art