Once the tent is up and you've laid out your kit, next job is to locate the nearest loos. Portable toilets (the best available!) are brought on to the sites and placed in groups, with floodlights for night-time use. Ideally, you will have a pitch that's near the loos ... but not too near! They inevitably smell (especially in hot weather), get muddy (in wet weather) and are noisy. The generators keep going most of the night.
Having got your bearings, and memorised where your tent is on the campsite (it can be confusing later, after dark), it's time to head off to either the village or the music field, depending on the time and your inclination. On your travels you may well spot food-and-drink tents and kiosks around the camping field, but don't count on them to be open when you are hungry! You'll also see shower cubicles (or, if near the sports club, see adverts for the use of their showers). Why people can't go for more than a couple of days without a shower amazes me, but many obviously don't feel human without taking a dip. However, be prepared to queue if you do.