Let me explain the guild system to you. A cargoship captain who wants to be taken seriously should be part of the guild system. This will show the quest posters that you are serious about your job and it will open up higher jobs, with higher pay and respectability. You will have your insurances in place and the guild will help settle any dispute between a job poster and a job taker. Also, you get a discount on ship maintainence in most shipyards. 

You can chose not to be part of a guild, but your quest choices will then be limited to crappy quests, the rare individual and bounty hunts. On the upside: there is no upside of operating outside the guild if you intend to be a law-abiding citizen.

Each guild quest will earn you guild points. Most quests will earn you around 100 points, though some special quests can earn you more. If you get caught breaking the law, if you are late on delivery or encounter other serious problems on a quest, you can, in addition to being fined, lose guild points, even be demoted. 

There are five guild levels (though a sixth level is rumoured to exist)
Level 1: 0-200 guild points
Level 2: 200-1000 guild points
Level 3: 1000-5000 guild points
Level 4: 5000-25000 guild points
Level 5: >25000 guild points

Uncle Ben can explain how you become a member. You met Uncle ben while still travellingbbefore you settles on the current planet. He helped your mother out here and there, as she was a struggling single mother. Your mother kept in contact with him even after settling down