Newbie programmer here, trying to wrap my head around OpenSL ES on Android using the NDK.

I’m usually able to solve most of my own programming questions through trial and error, but I am having trouble figuring out how to correctly use SLVisualizationtItf. Is there any sample code where this is used? How do I correctly create and set a callback?

That interface is not supported by the Android native audio APIs based on OpenSL ES 1.0.1.
For a list of supported interfaces in the Android implementation, please install the Android NDK and then see
$NDK/docs/opensles/index.html section “Supported features from OpenSL ES
1.0.1”, subsection “Objects and interfaces”.
Note that the Android implementation does not support one of the 3 standard profiles.