Your ultimate goal as a space trader is to amass enough money so you can buy your own moon, then claim that moon to retire to it. You need a lot of money for that, and will encounter many dangers, so along the way you might want to buy a better ship and better equipment. At first, the main point is to stay alive, and earn some money by trading. The GGF has a space port in every solar system, where goods locally produced are sold, and goods the locals need are bought. A good trader will judge, based on the systems tech level, government type, resources and current situation, which goods are cheap and which are expensive in a system, and will adapt his trading strategy accordingly. Later on, when you are better equipped, you might try to become a bounty hunter alongside your trading job. If you feel so inclined, you might also become a pirate and rob other traders of their goods.