Hello Brezina!
Welcome to the community!
I can’t speak for everyone, but from my experience - EXPERIENCE, is the best teacher. 
My trajectory to Sr. IAM Engineer was Desktop Support > Practice Powershell > Security Analyst > Practice Java > IAM Analyst > Practice Beanshell in IIQ > IAM Engineer > Practice APIs > Sr. IAM Engineer
I think if you stick around this community and try to answer questions here (even if your wrong) the experience you will get will launch you farther than trying to theorize or just study. If you have the option to experiment with IDN in a live environment, DO IT. Chase your curiosity and you will go far! If you don’t have that, start a blog explaining your journey and trying to solve problems here in the community.
I always say: “we learn by constantly solving hard problems. Trying to “prove” the “thing” yourself, instead of just accepting the answer.”
Good luck! We’re here for you and can’t wait to see what you become!
Welcome! 