to start you have to throw the line with the first and last post, once you have the reference line you get level and that marks the unevenness of the terrain and what you are going to have to lower or fill in, once this is done it should be the work must be even in height and neat ... I hope it serves you
I guess you are talking about the mesh.
If you bury it, it will oxidize. Some what they do is leave it very close to the ground and then with some tables of each side separated 5 or more CM, fill with concrete, as if it were a mini chained, about 15cm high, so that it is the concrete that rests on the floor.