I always have a hard time coming up with projects as well. I'd say try Rustlings to get a more interactive experience with it. Next build an API with Actix Web. I found interacting with a database and a front end helped me understand Rust to a deeper level. Good luck.
At the point I'm at now. I'll probably use both. Depends on the engagement and if the content is there. I'd much rather use Lemmy, but I'm not going to deprive myself of content.