What is mean the presence of one plus(+) amorphous phosphate in urine?

Not significant: Urine deposits when looked under microscope may show crystals of chemical products excreted by the kidney. This has no particular significance, so you can ignore it. Some people are prone to make kidney stones. In these folks we look carefully if they have excess of any stone forming chemicals. This is not one of them. So you do not need to worry.