"Father and mother, good night!"
Duolingo has "爸爸和妈妈要热水". It doesn't have "爸爸也妈妈".
"和" joins similar words in conjunction, e.g. two nouns or pronouns, or two adjectives. (It can join two verbs in certain circumstances, but the rules are a little complicated, and this is a more advanced grammar point.)
"也" modifies clauses. This isn't always straightforward. For example, Duolingo has the sentence "我很高，也很漂亮", but we can think of this as two clauses with the second subject implied.
Skj17 has the right idea with "和" being like "and" and "也" being like "also", though the usage of "and" is broader than that of "和", and "也" can often be translated to "and also".