What would be the acronym for the word praise?

An acronym is used to abbreviate a phrase, not a single Word. For example, SF for San Francisco (or Science Fiction), BART for Bay Area Rapid Transit, NATO for North Atlantic Treaty Organization. You will note that each Word of the phrase being turned into an acronym is represented by its first letter. If you had a phrase that included the Word prayer, then prayer would be indicated by a capital letter P. So for example, the Excellent Prayer Group would become EPG. The Fundamentalist Prayer Foundation would become the FPF. But prayer by itself does not call for an acronym.