How does the blueprint on the side-scroller example work exactly?

Skipping formal welcome. (Some hate it)

Ok so its my second day with Unreal Engine and im new to blueprints style of coding.
I have been watching the “Official” Blueprints tutorial on the unreal engine channel.

From there i wanted to edit (and see) the example side scroller-project.
But i am not sure how exactly its working. It looks as though allot is missing?

Is it mirroring the character once it moves left?
And when i click these notes there are no extra values that i can change.
Bit confused on how this lets me even change things like jump height or speed etc.

Also since i am asking this question.
Is it possible to break things when i edit everything in my project.
Are there things that are connected to other projects?

Thank you for your time Reader,

VRF