Search https://lemmyverse.net/communities for any communities you may be interested in. Many of them have the same or similar names to reddit subs. Also, subscribe to !newcommunities@lemmy.world. Once you have a few, flip your feed over to “subscribed” and browse your custom feed. Occasionally pop back into All to see if there are any other good ones you may have missed.

If you hate the web version of lemmy like I do, check out the mobile apps, which tend to have a more reddit-like design.

And once you’ve done all that, the only thing left to do it shitpost.