Would really like to go for the first time, where would I find tickets? I've seen you can buy them on www.ticketnet.fr, but there seem to be only single tickets. Anyone knows if all-event tickets are also available (and maybe a little bit cheaper..)?

Is it also possible, to buy tickets outside of the arena? Would be very greatful for any information, as I'm a complete beginner with these kind of things!
Thank you!