All campsites will have ample toilet and shower facilities, as well as access to drinking water. After that it may vary depending on what specific facilities each Sports Club has or chooses to provide.
For example, some may open cafes for breakfasts, drinks and snacks; some will have bars with big screens to be able to watch Olympic Events you don’t have tickets for; some may sell some basic groceries; some will do BBQs in the evenings.
Once the camping pitches go on sale it will be very clear what facilities are available as each campsite will have their own profile with everything you need to know. You can then easily make a decision about which is right for you.