Haya = present subjunctive of the ever-so-hard-to-pin-down verb “haber” (to have, to exist, etc.), Halla = person present tense of the verb “hallar” (to find), Allá = the adverb “there” or “over there.
"American language vs the British language. People of Britain call items weird things compared to here in the United States. The creators of the ENGLISH language can call things whatever the fuck we want, thanks!