Want to go on holiday to barcelona?

Want to travel to Barcelona this summer to see some friends I know over there but I'm 17 can I just book a flight and hotel and go or will i get stopped from customs or anything? It wont be a package holiday I know i need to be 18 to book one of them with thomson or someone but it would be booked seperatly I can fly with easy jet alone beacuse their policy allows anyone over 16 to fly alone. Please allow any sources to prove to me your oppinion thankyou!