if i have 2 astral herons on a bf, played my first card to float the trigger, can i use a reaction speed card to claim the discount of heron 1 and use another card for discount 2 is there any limitations of this and where are the windows where my opp can respond is the triggered ability of heron able to be reacted to or is it an invisible trigger if so can i react to my own trigger

Short answer: heron's trigger is a normal, visible chain item you (and your opponent) can respond to — but you can't split the two discounts the way you described. If you let both triggers resolve before playing your next card, both discounts lock onto that same one card: [4] energy and 4 [A] less total (FAQ #11679), and you can't redirect one of them to a later card.

The only way to get them on separate cards is timing. Your first card has to resolve first (if it's countered nothing triggers), and then both Heron triggers go on the chain as two separate chain items. If you play a Reaction card in the priority window after the first trigger resolves but before the second, that card is "the next card you play" and claims one discount; the second trigger then resolves and its discount applies to your next card. Because a trigger is still sitting on the chain, the state is Closed, so that in-between card must be Reaction-speed (Reaction spell or Reaction ability) — and costs can't go below 0 (Rule 356.6), so any wasted discount is just lost.

On reacting: yes, triggers on the chain are public and respondable. You can react to a trigger like any chain item, and you can react to your own trigger too — you get priority as controller of the newest chain item (Rule 312.2.c). Your opponent's windows are: when you play the first card (Closed, Reaction only), while the Heron trigger(s) are on the chain, and when you play the discounted card. Killing Heron in response to the trigger doesn't cancel the discount once it's on the chain (FAQ #11829).