This makes no sense and i can't figure out either of these!!!?

1.

First a definition. The intrinsic brightness of a star is how bright the star would appear at some standard distance. Knowing this brightness, and knowing the brightness you measure, you can figure out how far away it must be. It looks like this is what they mean by "luminosity".

So if the object has higher intrinsic brightness, it's farther away. If it's twice as bright, it's four times as far, due to the inverse square law. This assumes that the measured brightness is the same.

2.

Invert and convert to years. You could use the conversions that were used to convert 71 to 14. 1/71 = 0.014, so you have to multiply by about 1000.

So 1/500 = 0.002. And multiply by 1000 and you get 2. 2 billion years.

Hubble had a very young universe. In fact, it was pretty much known at the time that the Earth was older. You'd think "how embarrassing". But getting within a factor of ten was pretty impressive. And it turned out that nearby galaxies were used in the estimate, and many of them are gravitationally bound to us.

It was actually a good thing that Hubble was inaccurate. That meant that getting better measurements for better results was a reasonable thing to do. I mean, who could stand up to the Great Edwin Hubble? Well, it was known that one could do better. Aristotle was unassailable for a millennium. One could say that Aristotle held back science for that whole amount of time. Of course, he had help.