Connecting flights alone with 2 yr old and 12 month old. Help?

Hi everyone, I need some help. I haven’t flown since having my daughter over two years ago, but I’ll be taking an 8-9 hour trip soon with a connection of 2 hours somewhere in the middle. I’ll be alone with my 12 month old and my 2 1/2 yr old.

I really need advice on what to do, how to manage the airport, flight, connection, diaper changes, meals etc. Anything to help me envision and manage possible scenarios in advance.

I’m thinking I’d like to have my double stroller and car seats at my destinations so I need to take those.

If anyone has taken a similar trip, please let me know your tips/tricks/products that have helped you.