1) and 3) are correct. You can say "alguna" or "algunas", depending if you want to specify that you know more than one product, or want more than one fruit. Both singular and plural would be correct, grammatically.
2) is not correct, in my view, because "ayuda" is not a countable name. Alguno/a(s) means "one or more", so it's for countable names only. Ayuda, as stated in another answer, is better said with "algo de ayuda" or "un poco de ayuda".