I need help in Excel...

I have an excel sheet which has four tabs. On 1 of the pages (see image 1) I want to insert the following text 'Is this a service, calibration or repair ? into cell B3. Then in cell G3 on the same page I want a drop down box where you select either Service, Calibration, Repair - No Cal Required or Repair & Cal.

If Service or Repair is selected from the drop down box I want E-F41 and H41 on a different tab (see image 2) to show as n/a.

If Calibration or Repair & Cal is selected from the drop down box I want E-F41 and H41 on a different tab (see image 2) to show data copied from a cell in a different tab.

If you can please help this be achieved it would be appreciated.
I would like written instructions or screen shots on how to achieve this and also support where needed.