Loos and water
Many people find that if they are visiting their wood a lot, and particularly if they are camping at all, it is worth making an "earth closet". This is basically a hole in the ground with a seat over it. If you have a container of old ashes from the campfire you can use this instead of a flush! A sight-screen, which can just be some big piles of brash, is essential, or you can secrete it behind a handy rhododendron. Other people just keep a spade and roll of loo paper available and to hand. In the long term, there are more sophisticated systems but the majority depend on one of these basic plans.
Most people bring drinking water with them, either from their own taps, or from the local supermarket. Water is however very heavy to transport, and for washing you can seek a more convenient source. If you have no stream or lake to scoop water out of, you can collect rain water without a lot of trouble. If there is any structure, like a firewood shed, that has even a small roof, you can collect the rainwater in a gutter and run it into a container. Otherwise a tarpaulin slung between trees can be coaxed to do the same job. A barrel with a dark porous cloth stretched across the top will keep out leaves and stray insects, and in the dark the water is less likely to turn green.