If you don't receive your verification or reset email, read this Apple Support article: If you didn't receive your verification or reset email - Apple Support
"When you make certain updates to your Apple ID, we’ll send you an email to help you complete the update. For example, you might have reset your password, reset your security questions, or added a new email address to your account."
If you find you can’t sign in, reset your password, or receive verification codes, you can request account recovery (read this support article: How to use account recovery when you can’t reset your Apple ID password - Apple Support ) to regain access to your account. Account recovery might take a few days or longer, depending on the specific account information you can provide to verify your identity. More detail in —> Activation Lockout Issues - Apple Community
This page has telephone numbers for contacting Apple for support and service ➞ Contact Apple for support and service - Apple Support
Yes, of course you can't get access to the old account data from your new account, any more than I can when using my account. Each Apple ID is considered to be a different person with all the security barriers between accounts. To get access to the data you will have to regain access to the account so you can turn on sharing.