Do your part, try not to lurk!
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