My partner and I have bought a house, it's ~1970 construction, and underneath the carpets there's hardwood.

We've removed all the carpets and underlay, and the floor is in really good shape, short of staple/nail holes. There's not much for scratches and all the glue/tape etc. for the underlay seems to be coming off easily.

I was wondering if anyone could advise whether there's anything we can do to to care for this hardwood or not - should we be thinking about filling nail holes (staple holes are tiny) or resealing the floor?

There is a colored putty available for filling nail holes. Press the putty in with your finger or thumb to fill the hole. Lightly rub the spot with the ball of putty to pick up the excess.