Excel VBA refresh closed workbooks

Hello,
I am using Excel 2013 (.xlsm files) and I would like to see if there is a macro I can create that will automatically open Excels (in the folder, 13 files), refresh pivot table in the first sheet, save and close.

There are many similar forum topics on this topic, but none of the code does not work for me. I am a new VBA user, so it would be good to have the code as simple and understandable as possible, where I need to chance something to make it work.

The location of the folder containing the excel files is here : C:\Users\tomin\Desktop\Map

Thanks for help.