distances - What would the night sky look like if Earth orbited an intergalactic star?

Planets, if any in that star system, would be visible to the naked eye, the way you can see Mercury, Venus, Mars, Jupiter, Saturn and Uranus in our system. On a virtually empty sky, they would draw that much more attention.

Of course, if you had a Moon (or several moons), that would be visible too.

Very rarely and briefly, asteroids passing by very close to the planet might also be visible. In an empty sky, that would be a big event - and difficult to explain with an under-developed astronomy.

Comets would be visible as usual, if the system has an Oort cloud and enough perturbations within it.

Other than planets, moons, asteroids and comets:

From a desert, or a farm way out in the boondocks, you will see the nearest galaxies as faint "clouds" of luminescence in the sky, the way you can see Andromeda now from Earth. Any light pollution from cities nearby would kill it.

There would be no individual stars visible to the naked eye, since all the stars you can see that way must be very, very close (within your own galaxy, if you're located in one). It goes without saying that naked-eye star clusters that you can see from Earth (like the Pleiades) would not be visible there.

There are nebulae visible to the naked eye from a place far away from cities on Earth, like the Great Orion Nebula, but there would be no such thing visible from your star system.

So most people (city-dwellers) in a modern civilization in a place like that would not see anything in the night sky except planets (if any).

Keep in mind that the Milky Way and Andromeda are fairly close, as galaxies go. If your system was outside a cluster, and had no planets, then the sky would be completely empty to the naked eye no matter where you're looking from. Only telescopes would be able to see anything.

So there could be a civilization that exists in which the night is completely void of light?

unlikely but yes (unless they make telescopes)

that would suck

yes

It may also retard the development of astronomy, cosmology and fundamental physics - especially if they had no other planets and moons.