Are you distinguishing between the two meanings of 'there'? It can be a place word, in contrast to 'here', but probably much more commonly it's the subject in statements that things exist: There's a fly in my soup.
so you say that "there's" it's used as "subject in statements that things exist"
while "here's" is used much more to express "being here now"?? or as in this sentence " Here's your seat." what does it express?