Formula to help analyse data between sheets

OK, everyone was very helpful last time I asked something, so I'm hoping you can help again!

I have one large spreadsheet of a list of people each with a register number.
The second sheet will have all the numbers in order and will analyse the first sheet.

I've attached a sample spreadsheet which will hopefully explain.

I want the Analysis sheet to check the Data sheet, using the register no as the common value, and do the following:
1) Record the age in Col B.
2) Record the occupation in col C if it is not Army or Navy.
3) If the occupation is Army or Navy I want it to record it in column F instead.
3) Put something in columns D and E for me to be able to calculate how many boys had parents who were dead.

I have no idea if this is all possible, hence my question.
I have very limited knowledge of Excel, so please be patient if I'm asking the impossible!!

Many thanks



Test Spreadsheet Analysis.xlsx

See attached, I provided two solutions for you.

1. Formula to find the stuff you need
2. Use pivot table for more powerful analysis. I recommend using the pivot table. Be mindful of the slicers, if there's a filter in place, the slicer will have a red x in the corner.

Thank you so much hemesh, that is absolutely brilliant. Many, Many thanks

igoodable, that is great. My next step was the analysis and I wanted to use the pivot tables.
I've tried these before, but you've so helped me. Thanks you so much