First, check to see if you have an account activation email in your inbox, or your junk or spam folders. When you sign up for an account, we send you an activation email with a button you have to click on to activate your account. You won’t be able to sign in until you’ve done that.
If you don’t have an email from us, try to create your account again. If you did create an account and you have activated it, but still can’t log in, click the “Forgot password?” button on the login page to reset your password, and try logging in again.