if you use Shuriken Flip to move heron from base to battlefield. does it count as at the battlefield when it resolves for the discount on next card? or not because it was at base when you played the card

No — the trigger never fires. Heron's "if I'm at a battlefield" check happens the moment you play Shuriken Flip (when it goes on the chain), not when it resolves. Heron is at base at that instant, so the condition isn't met and no discount is created — moving him to the battlefield afterward doesn't retroactively trigger it (Rule 383.2.c; FAQ #11906).

This is the mirror image of the bounce rulings: once the trigger has fired while Heron is at a battlefield, moving him later doesn't cancel the discount — but if it never fired because he was at base, there's nothing to save. You need Heron already at a battlefield (or move him first) before playing your first card.