6 hour flight next week tips ?

jay
Hey I'm going to California next week with my 5 month old baby. It will be just the two of us my husband will be driving us to the airport 2 hours away and the flight will be 6 hours any tips first time flying with her. I'm planning on checking in the stroller and car seat at the gate but I will be carrying her. Anyone that has any advice it will be greatly appreciated I'm so nervous.