What should one expect the first time they ever lose a loved one?

Based on your own experiences, if someone (an adult) asked you what to expect the first time they lose a close loved one, what would you tell them? What advice would you give them for when that time comes? What experiences could you share that might help or ease the grieving process? I know everyone experiences the death of a close friend or family member differently, but what would you say to someone who is clueless as to how it feels and what to expect and wants to know for the future?