Extract info from tab sheets to master sheet

Hello,

I have attached a copy of a Sales workbook that I am trying to create a code for. The Sales Workbook will keep track of a master sheet, which should hold all Customer Names, Zip Code, and assigned Sales Rep compiled from the other 11 sheets (broken down by Sales Rep and named accordingly).

What I would like done is:
--To be able to enter in a Customer Name, Zip Code, and Rep name under a sheet that is NOT the master sheet. I would like to be able to have a code that after I make changes in Excel, either I can run to check for new entries and automatically add them to the master sheet, OR when I open Excel each time it checks for changes that I made last time I edited the document and will automatically update those changes before I even start to edit the document again. I don't want to have to enter in the data on the master sheet and the individual sales rep sheet as well.

Pretty straightforward. Only other thing to mention is that the master sheet will have columns with check boxes (this will keep track of which months the Sales Rep had phyical contact with the Customer). These boxes will not appear on the other sheets.

Can someone please help me as I am very stuck on how to even approach this..I have included a few customers into the tab named "John C" as an example. I would like the master sheet to pull that info and fill it in on the main sheet.

Thank you in advance!