travelling with a baby and a toddler

hey ladies! I recently relocated far away from my parents and would love to plan a visit to see them shortly after I have my baby. I also have a 2.5 year old. I've only been on a plane a couple times a few years ago so I'm not sure what to expect. can I bring my babies car seat? I assume if I did this, I would need to pay for a seat for them? do they have people at the airport who can assist me getting off the plane and down to baggage since I'll have my hands full? I will.also most.likelly need a csection and would rather travel sooner than 6 weeks so do they have wheelchairs to help?