How do I take my money out of Coinbase?

From a web browser:

For US customers, Coinbase uses the ACH bank transfer system for transfers to your bank account. The ACH bank transfer system typically takes 3-5 business days to complete after initiating a sell or withdrawal. Coinbase will deduct the balance from your source of funds and begin the bank transfer immediately.

Why is there a hold period? To protect your account and to ensure the integrity of our trading system, we may place a hold on funds leaving the platform – particularly if you purchases crypto using a card or if we detect abnormal activity or security concerns with your account.