Noun conjunctions come after the nouns they join, yes.
(Whereas sentence conjunctions come between the sentences they join.)
This course only teaches the conjunctions for "and" (je for nouns, 'ej for sentences), and their usage is describes in the tips and notes.
Are you reading those? If you're using a mobile app, they are probably not available, so you may be better off using the website, where they are accessible by clicking on the lightbulb icon after selecting a unit:
I wish there was a way for us to give more than a simple right/wrong answer on this kind of sentence. In most cases the order of the nouns is arbitrarily chosen by the composer of the sentence, and thus the order in the translation is unimportant. But sometimes the order is specifically chosen for some effect and then the order of presentation should be maintained. Without any context to indicate whether the order is important, we have decided to teach that it is always important. Thus you should always keep things in the order presented unless there is a grammatical reason for changing the order.