The official Star Wars YouTube channel playlist for Andor:
https://www.youtube.com/playlist?list=PL148kCvXk8pC2fMmEFdKns2Zvyvob6h9X
Star Wars Explained | Everything You NEED to Know Before Watching Andor
https://www.youtube.com/watch?v=rLMKsI2zjOA
I would add that it is worth watching the first 3 episodes of Andor in one go, as it was released to be viewed that way.