For more cargo buy at least one ton of rubbish and go to a system where you won’t be caught for dumping it. Then go to the cargo
screen and click a bit below the rubbish box. You should notice
that the remaining cargo has gone up but the ammount of rubbish
has stayed the same. Keep doing this and soon you’ll have enough cargo space to get a large plasma accelator. If you do this in a small ship, eventually you’ll be able to buy a class 7 hyperdrive and jump a long way across the galaxy with somewhere around 50 tons of fuel.