If you are not able to log in and you are not receiving a password reset email, it might be because you do not have an existing CNBC account under your email.
Signing up for a newsletter does NOT automatically create an account on CNBC.com, so that may be the reason for this confusion. You meed to take the separate step to create an account.
You can subscribe to CNBC Investing Club and register a new CNBC account by going here to this page and following the prompt to create an account before completing your purchase.
You can use the same email you are currently using to receive the newsletters or you can choose a new one.