We launched some threads dedicated to specific topics last month, you should find some communities that are interesting to you
https://lemmyverse.net/communities
Trending communities: !trendingcommunities@feddit.nl (make sure you enable "Show bot posts" to see here)
If you're really looking for newly created communities...
sorted by new https://lemmyverse.net/communities?order=published
Lemmy's built in communities page sorted by new /communities?listingType=All&sort=New&page=1
Scroll by new, rather than active, and scroll by Local, rather than All.
Browse all and sort by new or scaled maybe?
You can also use https://quiblr.com/
More details here: https://quiblr.com/understanding_your_private_personalized_feed
There is also !communities@ponder.cat for yet another source for new communities you might not be familiar with.
Support / questions about Lemmy.