hello, i am a lady tring to save some money and build my own computer desk, the catch is im having a little touble figuring out a plan to go about making one could someone please help me?

We had a privacy fence built from lumber by a professional builder. When the lumber was delivered we noticed that all the boards had white discoloring all over them. We asked what it was and the person building the fence said it was where it was treated and it should be gone in a few days. Well, it has been almost a month and none of it is gone. In fact looking at it closer appears that the white discoloring actual is where the lumber has been removed somehow. Does any one know what this is???? Also, the knotts in the lumber is seeping sap. Is it normal for sap to seep through the boards that are now my fence? We would appreciate any one's help in these matters. Ralph & Connie