Thanks for your post and welcome to the forums. It's really great having you on board with us in the Community.
I'm sorry to hear that you are having an issue with accessing some websites. There's a good chance this would be down to the Parental controls on your account so please follow the advice given to you above by enlli.
If this doesn't work and you are still having issues, pop back here to let us know so we can look into this further for you.