Niamh,
with your space travel agent, be sure to print off some of the space travel agent destinations from here:
https://exoplanets.nasa.gov/alien-worlds/exoplanet-travel-bureau/?intent=021
such as this one:
An older class might make travel brochures for the solar system, which your class could then use for selling the tickets and offering information to a potential traveller.
This is a guide that an older class might use: https://coppins6.weebly.com/