It’s all up to the individual. Whatever makes your motor run. But I’d universally suggest traveling to other countries to experience different cultures first hand. Other than that… Just interact with and experience as many new things as you’ve got the bandwidth for.
How would you prioritize what to experience? By novelty? Or would you be happy to watch every movie ever made?
I mention those because it’s a common trope in fiction for curiosity of experiences to lead down disturbing paths. Slanesh in 40k comes to mind.
It’s all up to the individual. Whatever makes your motor run. But I’d universally suggest traveling to other countries to experience different cultures first hand. Other than that… Just interact with and experience as many new things as you’ve got the bandwidth for.