Minecraft keeps reloading HELP DOESNT WORK

Hi I am in great need of help. So I bought Minecraft premium for the first time and when I got home I bought the code and everything, but when I downloaded it toy computer (pc) It wouldnt play I pressed the play icon button at the bottom of the screen then It just sat there without doing anything it was late at night so I decided to wait for the next day. So when that came I deleted the original Minecraft and downloaded it again when that was done I opened it up and pressed play then when the green bar made it to the end of loading it just highlighted the play button I pressed play again it did the exact same thing load then highlight play. Someone please help me I just want to play Minecraft again