Flying from CT to Cali in February and I’m so anxious!

I am so anxious of flying with my (gonna be 5 months) on a plane from ct to cali.. how do I go about it? It’s also middle of flu season and with all that “recycled plane air!? Do I buy a seat? Do I wear her? Do I pack my car seat? How do I bring formula? Where do I change her diaper? She’s not gonna be able to get the flu shot.. clearly

I need to take a deep breath lol