flying with a 10 month old. please help!

Ashlyn
I have to fly on a 3 hour flight with a 10 month old. Please tell me if I'm planning on this right since I've never done it before. I can't sleep bc I'm up thinking and stressing about it in the middle of the night and it's not for another month haha. 
So I was going to check her convertible car seat at the curb along with my luggage. Then use her stroller and check that at the gate. I'm nervous about when we get there because convertible car seats are like 25 pounds and we are renting a car so that might be tricky.
Any tips for me as a first time mom flying with baby? My mom is flying with me thankfully bc I will be 27 weeks pregnant when we fly 😳