Hello!
I notice that a lot of people are struggling with implementing Input Systems using Enhanced Input and Gameplay Abilities. Due to my struggling with it for like 2 weeks too, I created a small REPO containing a step-by-step tutorial on how to implement the Lyra Input System to help people like me learn it faster. However, I’m not that advanced, so there may be some mistakes. I’m aware that not everything is well explained, but I wanted to help some people with getting it to work 
Anyway grab a link to the REPO and good luck!