Start relaxed with breakfast at your son's place or pick up coffee and baked goods from the local bakery (most open from ~7:00am). It's a gentle way to recover from travel and meet neighbours.
Arataki Visitor Centre (usually open ~9:00–4:30) offers superb views over the ranges and short interpretive walks to understand the kauri forest and coast.
Ferry from downtown Auckland to Devonport runs frequently (early morning–evening); Mt Victoria offers short scenic walks and harbour views — ferries typically operate 7:00am–10:00pm but check timetable.
Ferries to Rangitoto depart from the downtown ferry terminal and the trip is about 25–40 minutes; island tracks are open daily though boat timetables vary seasonally.
Tours run regularly through the day (booking recommended); the guided experience of the film set lasts about 2 hours and is a unique cultural attraction.