How do I transfer ETH from Coinbase to GDAX?

As a cryptocurrency enthusiast, I'm curious about the process of transferring ETH from Coinbase to GDAX. Could you explain, step-by-step, how I would accomplish this task? I've heard that GDAX, now known as Coinbase Pro, offers more advanced trading options, so I'm interested in making the switch. Specifically, I'd like to know if there are any fees involved, the estimated timeline for the transfer, and whether I need to verify my account on both platforms before proceeding. Additionally, I'm wondering if there are any security measures I should take to ensure a smooth and secure transaction. Thank you for your assistance in clarifying this process.