If you were hypothetically traveling at the speed of light, according to our current understanding of physics, you would not be able to shine a torch or any other source of light ahead of you. This is because, at the speed of light, time dilation effects become extreme, and the concept of cause and effect as we understand it breaks down.
From the perspective of an external observer, as an object with mass approaches the speed of light, its relativistic mass increases, and time dilation occurs. Time dilation means that time appears to pass more slowly for the moving object relative to a stationary observer. Additionally, the length contraction effect would also come into play, causing objects in the direction of motion to appear highly compressed.
From your perspective as the traveler, time would effectively stop, and distances would appear significantly compressed. Therefore, shining a torch ahead of you wouldn't be possible since time and space would appear drastically different due to the effects of relativity.
It's important to note that the scenario of an object with mass traveling at the speed of light is currently considered impossible based on our current understanding of physics. The speed of light in a vacuum, approximately 299,792,458 meters per second, is an absolute speed limit according to Einstein's theory of relativity.