I'm going to the supercopa final match against Atletico next week and i read that the metro won't be available when the match ends, It is true? and what is the other ways to go back to the hotel? just taxies?
After the game, the metro won't be available indeed. Game ends at 1AM, and the metro in Barcelona stops 1 hour earlier, and the mayor of Barcelona refused to extend the opening-time of the metro with 1h to cope with Barca's ridiculous schedule.
Taxi around the Camp Nou will be impossible to get, there're simply too many people around Camp Nou once the game has just finished. Walking is your best option I think.
You could also try to take a bus at the Place Reial metrostop, but I'm not sure if the buses will still run so late, and if they are, there will be a mass of people waiting to take the bus, so not really recommended
Walking is your best option I guess; and beware of pickpockets!