Welcome to the Rebels in the sky wiki! If you are checking this out, that's a great start! An even better thing to do is to create a crew and then take a look at your first steps.
Rebels in the sky is an offline-first game, meaning that it works nice and well with no internet connection. However, some features like trading and playing games with other players require to be at least briefly online to connect to the P2P network and coordinate.