My wife & I will be visiting (mainly Northland) in March '24 and are looking for recommendations for campsites with walking access to fishing. I like to fish first and last light and will leave her to sleep in the campervan. I am looking for trout or coarse fishing between Aukland and maybe Cambridge for a few days. Then we head North for a couple of weeks. Trout fishing would be great to find in Northland but I am open to sea fishing from rocks or wharves etc. Thanks

Yip what MB said. Northland does have some pretty special wharf and rock fishing. You might want to get a 10kg-15kg travel rod and reel. Shimano has some good options that pack into your suitcase.

I don't think so, any remaining trout would have likely died of old age and there are no other species in the lakes of interest to the sports fisherman, unless huge eels are your thing.