You can pronounce it either as "å" or "åg", with the former being more common unless you're looking to stress it.
i think it sounds HAN here listen carefully. but some how i agree with you, some time it seems sound like HUM. but don't know where does it change sound.
You'll get used to telling them apart once your ears have attuned to the language. :)
You don't say "a bread" in English, you would say "a piece of bread" but that's a bit complicated for this early on I think.
Bread and water (brød og vann) are uncountable nouns which means they cannot be counted ("one bread", "two breads"; "one water", "two waters") and there isn't a plural form that pertains to the noun itself. However, you can say "a loaf of bread", "two loaves of bread" as well as "one glass of water" or "two bottles of water". https://www.ef.com/wwen/english-resources/english-grammar/countable-and-uncountable-nouns/ The same principle applies to some Norwegian words as well.
I'm assuming they don't, but does norwegian not have a difference between a/an? It doesn't matter is the word thsr follow starts a certain way?
No, it doesn't matter whether the following word starts with a vowel or a consonant sound.
However, there are three different indefinite articles in Norwegian, which correspond to the grammatical gender of the noun they modify:
en = indefinite article for masculine nouns.
ei = indefinite article for feminine* nouns.
et = indefinite article for neuter nouns.
*feminine nouns may be declined as if they were masculine, so they can take "en" in place of "ei".
Note that grammatical gender does not correspond with biological gender.
"Bread" isn't a countable noun. You can't say "a bread" and you can't use "en/et brød" in Norwegian. Therefore, "he has a bread and an apple" is wrong.