"He has bread and an apple."
Translation:Han har brød og et eple.
eple is a neuter noun, hence you need to use the indefinite article for neuter nouns: et.
en is the masculine article, ei the feminine one: en lov, ei hytte.
All three (en, ei, et) translate to a / an in English.
You will have to learn the grammatical gender of nouns in order to choose the correct articles, adjective endings and pronouns.
You can both say ei kvinne / jente (= kvinna / jenta in definite form) and en kvinne / jente (= kvinnen / jenten in definite form).
Et does not work here, as the nouns are not neuter.
Whether you regard them as (grammatically) feminine nouns or as masculine ones depends on local dialect, sociolect etc. pp. Norwegians allow much leeway with regard to the use of en instead of ei for (traditionally) feminine nouns.
If the verb (Har) comes before the subject, then it's a question.
"Does he have an apple?" - Har han et eple?