AC Odyssey: Do I need to know the previous AC? Assassin's Creed Odyssey Guide and Walkthrough

This is not required, because Assassin's Creed: Odyssey is, in fact, a completely different story - you can launch this game and enjoy it without feeling completely lost or confused. Of course, this doesn't change the fact that Odyssey will contain numerous references to the entire Assassin's Creed universe, and thus to Origins as well. Without any knowledge of the so-called lore, you may have a problem with understanding some of the issues raised in this cycle. Long-standing fans have the advantage that many things will be obvious to them. It's also easier for them to find different side features.

The eagle from Assassin's Creed Origins returns in Odyssey.

Knowledge from Origins also helps you to experience the game in general manner. Odyssey is a very similar product to its predecessor and although a lot of new features have been implemented, the core gameplay mechanics are practically the same.