Just keep going until you hit China. Five year old me will be blown away.

It would be far easier to hit up some near Earth objects, then maybe Vesta, but Ceres is the mother load. Small enough to be solid, but large enough to be spherical and therefore somewhat differentiated if you can get to the center of that Tootsie Pop.

Maybe in the process we’ll learn enough to effectively mine and utilize Phobos, the larger moon of Mars at 11 km in mean radius. That is the largest accessible orbital habitat that we have available (in flat pack IKEA furniture form) and it only has around 30-50 million years before it hits the Roche limit and turns into a ring, unless we manage to intervene.