The Biblical Book of Psalms is a collection of 150 poems and songs, each with their own individual authors. The word psalms means a "song accompanied by string plucking". It written over the 1050-600 BCE period, with minor edits continuing into the 2nd century CE. Multiple collections of Hebrew songs have been made for various purposes, and the Book of Psalms is a compilation of 5 of those collections.
73 Psalms are attributed to King David although modern scholars (and many theologians) know that most of them were not written by him, and perhaps, none of them were. But this attribution was popular in ancient times, and multiple New Testament verses also say (wrongly) that some Psalms were 'by David'. The psalms use lots of symbolism (much of which is now obscure) and are very open to subjective interpretation. Because of the varied authorship and vague text, it is not appropriate to use Psalms in doctrinal arguments.