Comparing two columns in two different sheets to find duplicate

I have been trying to work on this all day and I am getting now where. Any help would be greatly appreciated.

Basically I have data in two different sheets and would like to find the duplicates in sheet 1 and sheet 2, both column A. Sheet 1 has data that will change month to month while sheet 2's data will be constant. I would like to compare sheet 2, column A to sheet 1, column A and if there is a match, then pull the matching data from sheet 1 to sheet 3. (There will be multiple data on sheet 1, that will have the same number from sheet 2)

It would be great if I could get this to be automated, so that I can just drop in the data for sheet 1 each month and have it do it all.

I have included a sample sheet.

Any help would be amazing

Thanks