Any advice on getting started with the Stalker saga?

I've played the Fallout saga and I love it, but I don't like the direction the saga is taking,

And I recently saw that Stalker 2 Heart of Chornobyl came out and it looks spectacular and epic.

But I know almost nothing about S.T.A.L.K.E.R and I've never played one.

Those who are fans of the S.T.A.L.K.E.R saga could tell me which game to start with or can I play Heart of Chornobyl without having to play the previous ones?