We know that as you approach the speed of light, time slows down, if you were in a spaceship, time goes by quicker on earth.
Not quite, it's that things are relative ... and exactly which is travelling? Against what point? If you are shooting off at the speed of light in a spaceship, for all intents the spaceship is still and Earth is shooting off at the speed of light. You both see time relative to the other.
The problem with all the "everyone else aged" movie plots is that it ignores the return journey, where the reverse would be happening.
if you were able to travel at the speed of light, and you were to go to a planet 1,000 light years away, would you/your body/the spaceship 'age' 1000 years to get there?
You would be experiencing time local to you passing at the same rate in exactly the same way that if you are in the fastest plane, you still age by the exact time that you are in that plane.
The trouble with thinking about time and space in this way is that you assume a "now". There is no universal time of events in the universe to happen before or after others - you simply see things relative to your own locality and the further you look, the further back in time (your time) you are seeing things, but people there would see things where you are being further back in time.
Stick to euclidean space, it's what we're good at.