Learn Hardcore Russian: Я люблю порядок на рабочем столе.

Literally, я люблю means I love. But with abstract nouns like порядок (order, tidiness), it usually feels more like I really like / I like having.

Я люблю порядок на рабочем столе ≈ I like having things in order on my desk / I like my desk to be tidy.
It sounds a bit stronger than a neutral I don’t mind it; it implies a clear preference or habit.

You could translate it as either I love order on my desk or more naturally I like my desk to be tidy, depending on context and style in English.

Why is порядок in this form? Why not порядка or something else?

Порядок is in the accusative case, because it is the direct object of the verb люблю:

Я (subject, nominative)
люблю (verb)
порядок (direct object, accusative)

For inanimate masculine nouns like порядок, the accusative form is the same as the nominative:

Nominative: порядок – order
Accusative: порядок – (I love) order

You would see a different ending (‑а) in accusative mainly with animate masculine nouns, e.g.
Я люблю брата – I love (my) brother.