In order to protect your exchange account
(for example you have mentioned, Coinbase), you need to secure your email passwords, exchange password, and set up a Multi-factor authentication on both.
In order to protect your desktop wallet, having anti-virus installed can be considered just in case you have the habit of clicking and downloading at random sources. Or if you are not comfortable having anti-virus installed on your system, you can use the default Windows Defender (Windows 10) and be used to have a regular scan of your system via Malwarebytes scanner.
questions - from the scenario above, what is considered a "key"? which ones are secret keys? which ones are the ones that get hijacked and hackers steal your crypto? is the recovery list of words a crypto version for "forgot password"?
I don't know what wallet you are referring too but upon creating one, if there's a notice that you need to save those words, then just saved it and keep it to yourself. It's like protecting your other important credentials such as online banking, email, and even your Facebook account.
The list of words is your backup, not just only when you want to recover your wallet but in an event wherein you will use your wallet on another device.
I suggest spending time learning the difference between custodial and non-custodial wallets. You can make a conclusion about these keys, passwords, etc. after learning those.