At the very end of Bud, Not Buddy,our favorite traveling boy has settled into his new home and has started practicing on his new saxophone. He feels pretty good about his future as a musician. When he talks to his mother's picture, he says, "Here we go again, Momma, only this time I can't wait!" (19.168) and begins practicing again, thinking that Steady will be there early to give him his first lesson on the sax.
Deza Malone helped Bud see how he carries his mother all around with him in his memory. Now that Bud has let go of all of his mother's things—the flyers and the rocks— he can feel closer to her whenever he wants to without having to look at her belongings.
So what does Bud mean when he says, "Here we go again, Momma, only this time I can't wait!"? Well, he says "here we go again" several times throughout his story, which usually means that he is going to do something again that he hasn't liked in the past. Think back to the beginning when he is at the Home and about to be taken to the Amoses (1.45).
So, it may be that Bud is thinking about how he is setting off on another, happier journey. Maybe a journey to becoming a saxophone player? Someone special to a lot of people? Maybe it's his journey into adulthood with people who love him? We don't know for sure, but it seems pretty clear that Bud is excited about whatever it is that is taking off for him.
It makes sense that Bud, now being that full-open "flower" named Sleepy LaBone, would set his mind to doing something on stage, like performing music, just like his mother said. He wants to be "seen by the world" (5.42). Also music, it seems, is in his blood. Since his grandfather is a great musician, we can see how Bud might love it, too.
Finally, Bud thinks that Steady Eddie will get there early from his girlfriend's house because he seems just as excited to teach Bud to play the sax as Bud is to learn it. They're kind of like brothers now. And we just really like Steady, so we sort of want him to come back early, too. How about you?