I have only traveled to MEX and left the airport in the past, this will be my first time transferring to a domestic airline so have a few questions:

Delta - Aeromexico
flying Sunday
ATL-MEX-QRO

1)I need to change dollars.
Will this be readily available in both Domestic and International terminals?

2)I assume I arrive into the International Terminal and go thru customs and then will end up in the Domestic? I will be checking 3 bags,
what is the process for rechecking luggage thru customs and immigration?

3)The First Class lounge (am upgraded) in the International terminal is very very nice, but
I will only have access to the lounge in the domestic terminal, correct? Is food served??

4)My layover is 5 hours, mid-day.
If no food in the lounge, what restaurants do you recommend or other things to do?

5) Lost my sim card, need to purchase another:
will this be available in the Domestic terminal?