how do i make a mod remember where other blocks are and use that data

i made another post asking this but I didn't really see how it answers this part of the question (original here https://mcreator.net/tracker/issue/58684) so im asking again in the right place: how do I make the game remember what blocks it detected and where, and how do I make it call upon and use the data elsewhere. I know how to make it detect blocks, just not how to remember detections.