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.
¿Deber o deber de? Now we're getting to a more nuanced level! According to our grammar genius friends at "Deber" signifies obligation, such as "I must." "Deber de," on the other hand, suggests something less certain, such as "They probably.