I believe it is the beginning of the story
For example, you might hear about one cousin’s amazing new job, or another cousin’s basketball scholarship. This sentence is telling you details you might hear while at a family reunion— therefore making it a supporting detail.
He was seeking Utnapishtim, the only human being who was granted eternal life by the gods.
I am not entire sure what you need, but I will try to help you nevertheless. An affix is a term which includes both prefixes and suffixes - prefixes are added to the beginning of a word, and suffixes at the end in order to create a new word. So, let's say you want to add a prefix un- to the verb tie - you would get a new word <u />untie.