[title] ...and has very little experience with D&D. The last time he played was 30 years ago. Everyone at the table has little to no experience with 5e, except me, and I don't know the ranger class that well.
Then my foremost advice is: don't focus too much on the mechanics of the class, by the book, but on the role it tries to fulfill. Let your player do what he feels like fun with the ranger he envisions. You could give the player a list with the tasks/actions the ranger is specialised in (i.e. tracking enemies, foraging, scouting...) as a quick-reference card, instead of reading through the mechanics.
I'm looking for some general advice on how to build a decent Ranger with Hunter Archetype by using the PHB only . Advice on Spell choices would be very helpful.
I also think that the ranger is a solid class, even if it has some "ribbon" features. You need good DEX and WIS, and decent CON and STR. A Wood Elf can give your player more RP options thanks to Mask of the Wild. Whether he goes melee or ranged, it's up to him, although I would say going ranged is simpler. On good spells: Cure Wounds, Goodberry, Hunter's Mark, Speak with Animals, Enhance Ability, Lesser Restoration and Pass without Trace.
Also, how a DM could handle Favored Enemy and Natural Explorer abilities. Eventually, we'll be exploring The Isle of Dread (Goodman Games version) and i imagine that these abilitie will become super important.
Favored Enemy gives you advantage on tracking and recalling information (read weaknesses for example) about your fav. enemies, and a language they speak (if the speak one), so suggest him the enemies that appear more in the adventure, or the ones that are stronger.
With Natural Explorer I have had several problems during the years. First, you are an excelent explorer when you are on your fav. terrain, but when not, you are only as good as any other member. Second, being in your fav. terrain kills the exploration challenge because you can achieve anything you want just being 1 hour there. So, if you want to play it RAW, the advise is the same as Favored Enemy: suggest him the terrains that appear more in the adventure.
But if you are open for a little homebrew, and following my first advice, I would suggest you a simplified version:
NATURAL EXPLORER
You are a master of navigating the natural world, an unsurpassed explorer and survivor.
While travelling and surviving in the wilderness, you gain advantage on ability checks that use Nature or Survival.
At 6th level, your walking speed increases by 5, and you gain a climbing speed and a swimming speed equal to your walking speed.
It's simpler to remember, simpler to apply, and you are the best explorer although the chance for failure is still there (relatively small).