The first part is quite easy
list1 = {1, 3, 4, 7, 10, 12, 15, 17, 19, 24, 26, 29, 32,
35}; list2 = {2, 5, 6, 7, 8, 9, 11, 12, 14, 19, 25, 27, 29,
30}; position = Intersection[list1, list2]
There are probably more elegant ways to do the second part, but this works
Flatten[Table[
Position[list1, position[[q]]], {q, 1, Length[position]}]]
and
Flatten[Table[
Position[list2, position[[q]]], {q, 1, Length[position]}]]
Paul.