Super Mario Land 2 tells us that "after returning from rescuing Daisy from Tatanga" he sees that his castle has been taken over by Wario who locked the gate by scattering the six golden coins.

So we know where he goes after he lands the spaceship. The only question that remains is what does he do with Daisy in the spaceship (heeheehee haahaa!) and where does he actually land the ship? Does he land it in the Mushroom Kingdom where Daisy finds home in Peach's castle or does he let her off in her hometown before continuing home?