Right now the user count Lemmys is comparatively tiny when held up against reddit - but the user count isn't the thing that makes a social media site, it's the engagement
So even if you're used to lurking, try to get a little more active! Post memes, vote on posts, talk in the comments, whatever!
If people come here and see activity, content, and discussions, they're more likely to stay and contribute their own - if they come and see a ghost town, they'll just go back to reddit
One thing that might keep people off is how communities are created/duplicated on Lemmy. I mean you can have the exact same community but on different instances. Then you start asking yourself which one should I join? or perhaps both? This definitely will confuse people.
subscribe to all of them and play with the feed options and sorting order. it takes a little getting used to, but it seems intuitive once you're subscribed to a bunch of stuff. If the mobile clients develop this should become easier to manage from a UX standpoint.