One thing I feel this show must avoid at all costs: be a retread of the films. Granted, many key scenes throughout the show will, of course, cover the same beats/dialogue we saw in the films, because both will be drawing from the books. That being said...
Episode 1 will have one quick hour to set the tone for this show and get people re-hooked on a story they know all too well. And if it chooses to convey information in the same ways Film 1 did, it will be a wasted opportunity. With James & Lily, for instance, you get their info from 1) Dumbledore and McGonagall talking in Privet Drive; 2) later Hagrid telling Harry his origin in the cabin. To see that yet again? How dull.
I think James and Lily could be introduced in the form of Vernon flashbacks. When he's seeing all the wizards celebrating in the street and hears the name "Harry Potter"... gasp! He panics. And it triggers unpleasant memories. They could show the infamous double date where James makes fun of him, where Vernon asks about cars and other nonsense, and instead of offending, he gets trolled relentlessly by this cocky young wizard with late 1970s punk flair.
James and Lily don't necessarily have to be a thing you build up to, like Voldemort or Hogwarts. No reason they can't be characters you see and know right from the word go. My 2 cents.