POP3 email on Macbook Pro

You have to jump through a hoop or two, but it is possible:

1. Open "Mail" -> "Preferences..." in Mail.
2. Click the "Accounts" tab.
3. Click the "+" button at the bottom of the dialog.
4. Choose "Other mail account..." and "Continue".
5. Enter something non-existent as the email address, e.g. "does@notexist.com". Enter any password. Click "Sign in".
6. Mail will attempt to auto-configure the account and fail.
7. You will now see a dialog allowing you to enter the account details manually, including choosing "POP" as the account type.

In other words, you have to defeat Mail's account auto-configuration in order to enter the details manually.

Did you setup POP in gmail?

https://support.google.com/mail/answer/7104828?hl=en

Most people who use a computer and a smart phone use IMAP rather than POP so that email is synced across devices. But if you really want to use the older POP protocol follow the instructions at the link I provided.