Toril

The main inhabited world of the Realmspace system. Toril is the third planet from the Sun, with one moon, Selune, as well as the trailing asteroid field, the Tears of Selune.
Toril is the most cosmopolitan and Spelljamming-aware world in the Radiant Triangle, featuring several major Spelljamming ports and many societies engaged in wildspace exploration. 
For the Spelljamming Corps, the most notable port is Waterdeep on the Sword Coast, full members and sponsors of the Corps. It is requested by the city that all Spelljamming ships approach the city by water, and dock only at a particular marked wharf (known as the "star dock").
Calimport to the South is also a major stop for independent trade. Calimport is not rigorously regulated or ruled, but be warned that the local merchants can be jealous of Speljamming traders for fears that they will steal customers with exotic goods. Calimport is also favored by some less-than-scrupulous traders, which rumours suggest might even include Illithids.
The nations of Shou and Wa both maintain their own state-sponsored space programs, declining participation in the Spelljammer Corps and forbidding independent trade generally, but they nevertheless maintain their own fleets of ships and outposts throughout Realmspace. 
The Elven homeland of Evermeet is also affiliated with the Elven Imperial Navy. While Navy ships can be found occasionally visiting the island on diplomatic missions, the island is generally closed to Spelljammer traffic without prior invitation.
Lastly, the Mercane maintain their own independent trading outpost high in the inaccessible mountains of Wu Pi Te Shao, which caters mainly to starfaring traders not interested in interacting with the locals. A solid option for trading with the Mercane in the Radiant Triangle.