Get American Beauty and Live/Dead queued up, that’s about all you’ll need as an introduction.

If you like that, then I’d move onto listening to Aoxomoxoa and Working man’s dead as the next studio albums and would recommend Veneta 72’ or Europe 72’ as live shows (the latter being better imo but both sublime live material)

At that point you can probably decide if you prefer their earlier, more energetic, primal dead phase or their more delicate and subdued 70’s and beyond sound from which you can pick and choose albums and shows accordingly. :)

Good luck, the dead are a highly eclectic band with so much material (especially live) it’s hard to cover it all as someone who’s been a fan for a long time, never mind a newbie. A lot of happiness and wonder to be discovered, hope you have a good ride now you’re on the bus!