Space-stations will be many and large. They will be both in space and on the planets. Some will orbit planets and some will be in interplanatary space. Space stations that are not situated on planets will be circular as in the picture and they will spin to simulate a gravitational field.
The space-stations will be like cities, with transport systems, schools, entertainment, shopping centers, workplaces and all the usual services. People will live there just as they live in cities today. The stations will be clean and unpolluted because solar energy will be used to generate electricity.
In the future it may be possible to transport some of the more hardy plants to other planets like Mars and Venus. On both of these planets there is atmosphere that humans can not breathe, but if plants were planted there they might be able to create an environment suitable for life by photosynthesis. Then it might be possible for humans to live on the cooler parts of Venus or the warmer parts of Mars.