Updated: I think I have figured it out for the most part. Crated an NPC class that extends the Sprite class. Created an array of phrases - and did basically the same thing we did on the battle scene. Created buttons, grabbed the innerHTML of the buttons to populate the sentence text in a div down below. Still buggy because the buttons render twice for some reason sometimes - but not always...
(Updated: I forgot to replaceChildren() on function call. That cleared this issue up).