Generic “USB media players” used to be a big thing back before they were integrated into every TV, I’m fairly sure you can easily find one with a remote still.
It seems like a lot of DVD/bluray players still take USB too, we used to play off of an external HDD and USB thumb drives using our Blu-ray player when I was a kid. You can probably get something really good second hand too.
Well, data just doesn’t really flow at the speed of light. It’s a really really complicated thing to discuss in terms of physical circuits because the true picture involves considering how the EM field evolves. Electrons in a circuit move at extremely slow speeds, ~millimeters per second.
The good news is you don’t need to send information particularly fast to send it through time. Generally in physics, we build time travel systems by creating extremely curved spacetime that contains paths to the past, theoretically you could send light through such a path to transmit information back in time. As someone already mentioned, you generally need negative mass to construct these.
If you have negative mass there are three options I’m aware of:
If you want to send information into the distant future, you could get really fancy and scatter some light off of a black hole or something.