simple design for estructure wall for a encosure cheap but efficient

it should had a comunas and footings , above the footings its goes a 1,2 meter wall of cement Block (40cm x 20cm x 10-12-15)

There are parts where the terrain is flat and in others undulating


1-how far should the columns go? (as dar as they can but with out sacrificing quality and
stability)
2-Measurements and thicknesses of columns and footings?
3-how deep must they go?
4-design of the footings in which you can see what is buried and what is outside.


There is a image were you can see the kind of wall that im talking about and there is other with a design of mine