How do I know which trusted device I have on file

Trusted devices and trusted phone numbers are 2 different things.

Any Apple device logged in to your Apple ID is a trusted device. And will show up in your devices list in Settings ➜ Apple ID.

click here ➜ Check your Apple ID device list to find where you're signed in - Apple Support

A Trusted Phone number, is just that, a phone number, it does not have a specific device linked to it. It can be an Android device or even a landline.

To view your list of trusted items refer to the section: About trusted phone numbers and trusted devices in the document Two-factor authentication for Apple ID - Apple Support

To see, add, or change your trusted phone numbers:

- On your iPhone, iPad, or iPod touch: Go to Settings > your name > Password & Security. Next to Trusted Phone Number, tap Edit.

- On a Mac: Choose Apple menu  > System Settings (or System Preferences), then click your name (or Apple ID). Click Password & Security, then add or remove a trusted phone number.

- In a web browser: Go to the Account Security section of https://appleid.apple.com/