@Abu Sadeq policies and queries aren't designed to do the same thing. Policies need to be true/false, queries can return any data from the table they target. Please see these articles for further information about policies and some examples of how they're written:
https://fleetdm.com/policies https://fleetdm.com/policies.
If you'd like your queries to run on a schedule, you can go to Queries > Add query > Save in your Fleet dashboard. You can then set the query to run on a schedule, and you can view the results for previous runs of the query in that Queries page.