Hi all!

I am 22 year old female and planning a trip to New Zealand and need some help with my itinerary. So, the upshot is this: i've done a bit of travelling with my brother but never solo before, so I spent about a year saving and planning for a month long backpacking trip across Greece in late April to May and thought I was being smart when I booked flights well in advance through Qatar... turns out I wasn't. But, I took time off uni and geared myself up for a trip so now I'm turning to New Zealand.

I've never been, and don't know a lot about it and I am excited to go, but I'm going soon and need some help planning . I'll be going from 18th April to 12th May, so about three weeks. I'll be doing a tour for the first 9 days on the south island through Christchurch to Queenstown and back with stops in between at places like milford sound and franz josef glacier. I'm also going to Hobbiton on the 4th May so need to be in the North Island (Auckland) by then.
So I have 5 days that I can spend on either the south or north island (in between the end of my tour and hobbiton) and 8 days specifically on the north island after hobbiton and I fly out from Auckland on the 12th.Any recommendations or help at all with where I could go would be greatly appreciated!

I like adventure and love culture and anything new. I'm a huge nerd so I'll jump on anything LOTR of Narnia or anything else that was filmed there, but thats more a hobby and not the sole purpose for my trip. I probably won't have a car and yeah, that's pretty much all there is to know.

Sorry this is so long, thanks in advance for any help!!

Wellington for its fine museum, lively vibe and a few LOTR options such as the weta workshop.
Have you booked a Hobbiton tour that includes transportation? They are possible from Rotorua or Auckland, as well as Matamata. So you could bus from Wellington to Rotorua, enjoy some of the cultural attractions there, and do a day tour to Hobbiton. Or perhaps a tour including the Waitomo caves.