You only need the 24 seed words. Even if Trezor goes out of business, or your hardware device fails, you can still recover your funds using those 24 words, using any wallet software.

Passphrase is like an additional secret word in addition to your 24 words. If you didn't set up a passphrase wallet, you won't need to use the passphrase. If you did set up a passphrase wallet, you will also need to use the passphrase in addition to the 24 words.

The Trezor PIN is only for accessing the Trezor device itself. You don't need it for accessing your funds using non-Trezor software.