These are some answers from the Ask An Apologist forum about confirmation saints.
Are confirmation names required?
Why a new name at Confirmation?
To choose a patron saint, I recommend reading about saints and seeing if there is one that kind of ‘grabs’ you. Sometimes people just hear a saint’s story and just connect this it instantly. Other options:
-Choose a saint who is a patron of a hobby or interest of yours, for example if you are a musician, you could chose Saint Cecilia as she is the patron saint of musicians.
-Choosing the saint who’s feast day falls on your birthday. So for example if you were born on the 21st of January, you could choose Saint Agnes.
There are websites that have a ‘saint of the day’ system so that’s a good way to learn about different saints. The website catholic.org has an email saint of the day system.
I’ve never heard of people taking a patron saint of a different gender but I don’t know about if it’s allowed or not. If you have a male saint in mind, perhaps consider using the feminine form of the name.
These are some of my personal favourite saints:
Saint Agnes of Rome, virgin-martyr
Saint Emerentiana, foster sister of Saint Agnes and martyr
Saint Maria Goretti, virgin-martyr
Saint Joan of Arc, martyr