1. To find new communities - go to https://lemmyverse.net/communities, click the top right "Home" icon and input your home instance (ex: lemmy.world)... now you can open/subscribe to every community you like.

2. Get a good mobile app - they are listed here (with a ton of other great new-user tips): https://lemmy.ml/post/1470777

3. Change your default "Sort Type" to "Subscribed + New" (in settings) - now you have a fresh feed of your exact interests, every time you open Lemmy.

4. Communicate in a genuine, open-minded way - to me, Lemmy is a good place to really connect with people, and have honest discussions (versus the often more 'performative' tone of greeddit).

I made a community for Lemmy tips, called...well, !lemmytips@discuss.tchncs.de

If you're using an app to view lemmy, it's worth updating regularly (at the moment anyway). Mine hadn't automatically updated for a while, but it turns out Jerboa (on android) has made a lot of improvements to the app in the past few weeks

Be willing to learn a new social network.

Search for the names of all the communities that you're part of on reddit and join the biggest two or three with the same name that you see here. Post to whichever is your favorite or whichever is biggest if you can't tell the difference in order to encourage consolidation.