What comes to what you said about relativity isnt quite true. Its true that to an outside observer for example a spaceship thats moving away next to you sideways at the speed of light appears to get smaller and that the same spaceship moving closer to you(and passing by) at the speed of light appears to be stretched, also if the spaceship is at in front of you and suddenly starting to move away from you at the speed of light will appear to first stretch and then get smaller. But the whole idea about relativity is that all of this is relative to the observer.
Ill explain it and need this uber artistic picture to illustrate:
Those rings are photons that are emitted from each end. If the ship is stationary, the photons from each end will hit your eyes at the same time and the ship will look normal to you. Now if the ship moves at(or near) the speed of light away from you sideways(as pictured), the photons from the side which is further away from you will take longer to travel to you than the photons which are at the other end. So because the ship is moving away from you and you perceive the other side with a small delay, the spaceship appears to you as if it had changed size. Similarly if the ship is moving towards you, you will perceive the photons that are closer to you sooner than the photons that come further away, so you will perceive photon that is older at the same time than you perceive photons that are coming from the side which is loser to you.
You see this is hat happens:
The first box is where the ship is when you perceive the closest part of it, the middle box is there just because you see it there also(as long as there are photons coming all over the ship, not just the ends) and the box on the right is where the ship is when you perceive the side which is furthest to you. -> the ship will look as if it was longer than it is in reality because it is relativistic how you perceive things due to static speed of light.
If this didnt clear it out, feel free to ask for further explanation.
What comes to traveling long distances in a lifetime, well basically it is true, but there is a twist to it which doesent really go hand in hand with your other claims.
You see if you are moving at the speed of light, you are not aging because none of the atoms can work normally anymore. You see the proton that is spinning around the atom nucleus cant spin anymore, as it would be required for it to move faster than light in order for it to spin around the nucleus -> atom will stop and you will stop perceiving time and nothing changes until you stop and you wil end up in the other side of the universe before you grow any older. Obviously you cant get back and have moved through time, as time is nothing than distance which light travels and when you travel at the speed of time, time will pass around you, but not on you. The time that will pass around you depend on how many light years you travel, so if you move 10 light years, 10 years have passed around you and you have moved the distance which light moves in 10 years.