I always put a UV filter on my lens. Not for the UV pretection as it is a DSLR but to protect the glass. Cleaning cloth, poleriser filter.
Memorey cards would be the higest class you can get your hands on, i think that’s class 10
(also depends on how long your camera takes to buffer, shooting raw or JPG or both and file size)
Get more than one card, extra battery would be useful (stops you from crying in the woods) . ND filters (for that milky water effect and streaming clouds) and a external flash is a good option (Amazon YongNuo YN-560 III Flashgun. Please note it is a manual flash).
The main thing is to enjoy yourself and all the bits and bobs will come later :) Find a good book as well or a Youtube channel (OMG YT is a life saver)
Nikon owners are all cider and malabu drinks :wink: