The speed of light is a universal constant of 300,000 km/s2
We observe stars millions/billions of light-years away
A light-year is the distance that light travels in 1 year – the light we see today from a star 500 light years away is 500 years old
The furthest stars away are 10-15 billion light years away
We have telescopes that can see further, but there isn’t anything viewable