If you don't know what to learn, do something. Anything. It keep be as small as making your room 1% better than it was 15 minutes ago, or as broad and as deep as building that newsletter you've always wanted to start writing. The fact is that clarity only comes through action, as does expertise. Without doing or living in some shape of form, you're not acting, and therefore not making mistakes, so you're not learning shit. If you want to learn, do.