Receving email for signing up to sites that I didn't?

Alright, when I got this email that wanted me to validate my email for this adult website (Which I didn't even know existed) popped up and tried to use MY email and there was even a password with it. Should I be worried about this? I mean, whats going on? Is it a sign of something? I didn't validate it naturally..I use Yahoo mail.

Hi Doctor fix It, I think it would be best for you to raise this in the Classroom,and one of your teachers will be able to advise on the best way forward for you. Regards paws

Thank you very much.

Good luck!