Learn Dutch: Het is laat, dus wij gaan naar huis. - It is late, so we are going home.

In English, you say 'going home' without the word 'to'. In Dutch, when you go to a destination, you must use the preposition naar (to). So naar huis literally translates to 'to house'.

Does the word dus (so) change the word order in the second half of the sentence?

No. The word dus just links two normal sentences together. After dus, the second half follows the standard subject-verb order: first the subject wij, then the verb gaan.

Why does the translation say 'are going', but the Dutch sentence just uses gaan?

Dutch doesn't have an exact match for the English 'am/is/are doing' tense. The single verb gaan covers both 'we go' and 'we are going'.

Could I say we gaan instead of wij gaan?

Yes, you can. Wij and we both mean 'we'. Wij is slightly more emphasized, while we is the normal, unstressed version. Both are perfectly fine here.