Firstly, You need to contact your carrier and tell them that you need wheelchair assistance. They will arrange it for your return journey as well. You need to let them know at each airport, again search out the rep at the airport. TBH I don't think they will take you to the food hall, I think they will take you straight to the departure lounge...so arrange to take sandwiches or snacks with you.
The 3C's have a wheelchair which they hire out....If you contact Liz101 on here i'm sure she will help you.