VBA code that will open excel workbook(s) then copy only certain cells and paste

I am new to VBA and need help...

I have a macro that will open all of the workbooks and then open worksheets but I can't get it to:

As each worksheet is open copy only certain columns (only if the cell(s) contain a value)
paste it into the next available row starting in column B in a master file while also putting the tab name of the worksheet open into Column A
save the master file

My workbooks are separated out by month and then by categories. I have used a template so every month is set-up the same way.

I need to extract cells A1:A800 and X1:X800 (if they contain a value only)
examples:
January
cookies
cake
February
cookies
cake
I have looked at other posts and have tried to peice something together but keep getting errors with everything that I have tried.

Any help or suggestions would be great!