Hello @masambaghost
Given how vast the knowledge-base of Splunk is, I'm not sure what specific challenge are you looking for.
But I'd suggest it would be better if you'll take up Certifications since there will be timed-labs and best practices.
Courses Catalog:
https://education.splunk.com/
With this, you'll go through countless Modules which would build up your Splunk foundational skills.
Hope it helps!
... View more