According to Einstein's theory of special relativity, it is not possible for any object with mass, including humans, to move at or faster than the speed of light in a vacuum. The speed of light in a vacuum is considered to be the cosmic speed limit, and as an object with mass approaches the speed of light, its relativistic mass increases, and more and more energy is required to continue accelerating it. At the speed of light, an object with mass would require an infinite amount of energy to accelerate further, making it physically impossible to reach or exceed the speed of light.
Since it's not possible for any object with mass to travel faster than the speed of light, the scenario of one person moving at such a speed and meeting the other person in their past is not physically realistic within the framework of special relativity.
In special relativity, as an object approaches the speed of light, time dilation occurs, meaning that time passes more slowly for the moving object relative to a stationary observer. However, this does not allow the moving object to "go back in time" to meet someone in their past.
The theory of special relativity has been extensively tested and is one of the most successful theories in physics. It governs the behavior of objects moving at high speeds, but it also sets the limit on how fast objects with mass can travel. no experimental evidence supports the possibility of objects with mass exceeding the speed of light or traveling back in time to meet someone in their past.