Have you imported the tails-signing.key yet? Usually you can double-click on that to import it using whatever graphical gpg frontend is set up on your system. It may ask you how well you trust the owner of the key. You can answer that question however you want without affecting this verification process.
Next, it looks like you run the instructions from this page: https://tails.net/install/expert/index.en.html#verify
Some of those command line parameters look a little paranoid. The basic command you want to run is: gpg --verify somefile.sig somefile.img
If anyone was hoping for women priests, give up on that. The Roman Catholic church would first have to retract both papal infallibility and ecumenical infallibility.
They have made too many definitive statements that women can’t be priests, and they have made definitive statements that their definitive statements are infallible, and must be agreed to by anyone who calls themself Catholic. It’s not even up for debate (unless all of the infallibility stuff is also up for debate).
For example:
https://www.vatican.va/content/john-paul-ii/en/apost_letters/1994/documents/hf_jp-ii_apl_19940522_ordinatio-sacerdotalis.html
They really painted themselves into a corner. While the rest of society moves forward with equal rights for historically marginalized groups, the Catholic church will be stuck with the effects of their early bad decisions (and some recent bad decisions) because they banned themselves from admitting when they are wrong.