Easy Money
Buy an extra passenger cabin and then get a passenger. After you have done, try to sell your ship. You won't be able to, but keep trying as each time you do so your money will increase.
More Cargo space
This doesn't always work, but keep trying. In a space station, buy a ton of rubbish. Then hyperspace jump to another system. Then go to your Cargo Inventory screen, and you should see the ton of rubbish. Imagine another box just below that of the rubbish, then click on it. Everytime you do this, you will get an extra ton of space on your ship.
