Enroll

Create an Apple ID

Apple ID is the account to use in all Apple logins. Including in the developer account.
Apple ID
AppleI ID

Enroll in Apple Developer Program

You can enroll has an individual or organization. Please read carefully Apple documentation to understand the costs and benefits.
Apple Developer Program - Apple Developer
Apple Developer
The Apple Developer Program annual fee is 99 USD and the Apple Developer Enterprise Program annual fee is 299 USD. Values can change!
If you enroll as a organization you will need a D-U-N-S® Number. This may have costs and may take several days to get!