* A normal lunch at CERN costs about 15 CHF, inclusive of one coffee and one delicious dessert.
* You can pay with CHF and EUR in CERN (the drawback is always CHF) and most of stores and restaurants in Geneva
* The AC power plugs you'll find at CERN are SEV_1011 (https://en.wikipedia.org/wiki/AC_power_plugs_and_sockets#Swiss_SEV_1011). You can borrow one at the hostel reception.
* As guest you can only enter and exit the main CERN area through entrance B
* A bus ride from the airport to CERN is free of charge, if you take a ticket at the vending machine in the baggage claim area. Should you miss that vending machine, a ticket will cost you 3.00 CHF. https://genevalunch.com/guides/travel/the-cheerful-traveler-geneva-airport-public-transport/