I visited New Zealand for the first time. These are the biggest mistakes I made, even as a seasoned solo traveler
Splurging on a camper van without plans to spend enough time on the road

My first adventure in New Zealand was booking a camper van and taking it to a music festival in Northland.
It was cool to have a van, but I wish I'd planned more time on the road instead of leaving it parked at the festival for most of my rental period.
If I'd had a few extra days, I would have driven up to Cape Reinga to see the point where the Pacific Ocean and Tasman Sea meet. Doing this also would've helped the cost feel more worthwhile, since the rental wasn't cheap.
Not researching which side of the bus to sit on

New Zealand is renowned for its stunning scenery, but some bus routes have better views on a particular side.
Before each ride, I wish I'd looked into which side offered the best vantage points instead of realizing halfway through that I was on the wrong one.
Trying to schedule celestial sights

I planned stays in Lake Tekapo and Te Anau hoping to glimpse the aurora australis, or southern lights, but canceled both due to cloudy forecasts that would have made aurora chasing impossible.
After rerouting, I also canceled a hot pool and stargazing experience I'd confidently booked as non-refundable, which meant losing that money.
To fill this gap in my itinerary, I stayed longer in Queenstown, where I never expected to see the aurora because of light pollution. Ironically, that's exactly where I captured photos of the cosmic phenomenon.
All that said, next time I travel, I probably wouldn't book non-refundable excursions that are so contingent on weather.