First time flying

Danielle • Married for two years. Baby #2 dude august

We will be flying from Cali to Alaska to visit my family. It's a 9 hour trip including layovers. Any one have any tips when it comes to flying with baby?

I'm debating checking the car seat or lugging it around to hopefully get an empty seat next to us for the car seat. Also I'm scared the car seat will be lost and we will have to buy another one once we land.