The Voyager app has a built in “migrate subreddits” button. It’s not great but it works.

Try looking https://lemmyverse.net/

I primarily use lemmyverse.net with related terms till I find something. Otherwise I might create it myself till I can hand it off to someone.

Here’s the guide from !communityPromo@lemmy.ca:

A great way to find lesser known communities is to look at the /communities page on an instance. For example: https://lemmy.ca/communities

🌐 Instances to look through

• pangora.social (NEW): Great way to find instances related to a particular topic. This is also great for picking an instance when first making an account/moving accounts.
• awesome-lemmy-instances: not that organized, but it

🔎 Search pages

• https://lemmyverse.net/communities
• https://browse.feddit.de/ (run by feddit.de)

🔥 Apps and Browser Extensions

• Instance Assistant: Browser extension with tools to help you redirect & search for communities
• Voyager Migrator: Tool to help you migrate Subreddits
• Other apps: https://lemmyapps.netlify.app/

🙌 Communities for discovering new communities:

• !communitypromo@lemmy.ca: You’re here right now
• !trendingcommunities@feddit.nl: Daily posts with the trending communities from across the threadiverse
• !newcommunities@lemmy.world: Find out about new communities

Here are some other communities, some of which are less active:

• !wowthislemmyexists@lemmy.ca
• !lemmy411@lemmy.ca
• !findacommunity@lemmy.ml

Remember, you can also post questions about finding new communities right here!

👽 Coming from Reddit?

• sub.rehab: You can sort by official replacements & sister communities
• redditmigration.com: List from the migration
• quippd.com: Another list created by a user during the migration

Voyager client have a feature that provide you recommendation for communities similar to subs you follow on reddit

lemmy.world/c/noncredibledefense