People say if you travel with light speed then you may reach in the past (time travel). I think it is wrong. what you have already observed is gone or ended, travelling with speed of light you will observe everything frozen more accurately you will not understand the shape of surrounding object. you can not take left or right turn.
Whatever sort of lights come toward you will came two times faster.
Let say you are observing a star explosion which took place one light year far from you. So light has taken one year to reach to you. now you start to go there with light speed. you need one year to go there. when you arrive there you are actually two years late.