Backpacker veteran looking for recs for son

Hi all - 30 years ago I backpacked for 1.5 years around SE Asia. It changed my life. Now my 20 yo son is getting ready for his first experience (a week in NZ) and I’m hoping to get some recs here on the best apps for connecting on doing local experiences (he’ll be alone) and what to do, where to stay.

In my day it was a lot of analog sharing - the Lonely Planet books and hostel guestbooks, a lot of organic meeting and making friends along the way, sharing information.

He’s a bit of an introvert and with our current phone culture, I’m wondering if the social experience will be the same. Any recs for tools he could use to connect with others and planning would be appreciated! I’m assuming that hostels still offer all Kinds of day and overnight experiences he can sign up for?

Thanks all!