Learn Russian: Я не люблю ночной автобус.

It means both! When talking about everyday things, activities, or habits (like taking a bus), любить is usually translated as "like" to sound natural in English. It shows a general, ongoing preference.

Why is there an extra "л" in люблю? The dictionary form is любить.

This is a common spelling pattern. For many verbs ending in -бить, -вить, or -мить, an extra л pops up only in the "I" (я) form to make it easier to say. That is why it is я люблю, but the "л" vanishes in forms like ты любишь (you like).

Shouldn't the object of the sentence be in the Accusative case? Why is it just ночной автобус?

It actually is in the Accusative case! The verb любить requires the Accusative case, but because автобус is a masculine, inanimate noun (a non-living thing), its Accusative form is identical to its dictionary form. The adjective ночной matches this rule too.

Is ночной related to a time word?

Yes, ночной is the adjective form of the noun ночь (night). In English you can just put two nouns together to say "night bus", but Russian requires you to turn the time word into an adjective to describe the bus.