Don't need macro, could do this with data validation.
Have all the cells except the first set listed be locked (cell format - Protection - locked), then protect sheet.
For the downstream cells, you use a Data Validation formula like
=$A$2<>""
That will prevent anything from being entered until A2 is filled. If you need multiple cells to be filled in first, can do
=AND($A$2<>"", $C$7<>"")
and so on.
Don't need macro, could do this with data validation.
Have all the cells except the first set listed be locked (cell format - Protection - locked), then protect sheet.
For the downstream cells, you use a Data Validation formula like
=$A$2<>""
That will prevent anything from being entered until A2 is filled. If you need multiple cells to be filled in first, can do
=AND($A$2<>"", $C$7<>"")
and so on.