Is it not possible to change your avatar? Where are Personas? Song Structure Markers.

New subscriber here.

The website gives instructions to change your avatar, but the instructions provided do not function.

I also saw something on the website about personas but I don't see anything about that on the app. Is that no longer a thing?

I also found this reference (image) on another app for song structure markers. Can someone help me with any references I should know? Can you add instrumental markers etc to the song?

Anything else I should know?

Thanks!