When a closed value is selected in the OOTB salesforce component status picklist, I would like to Open a Modal Component. How would I go about doing that.
You can't do that with standard Salesforce functionality. You would need to work with Lightning Components and Platform Events or Change Data Capture events. I'm not going to describe the details, but the idea is that an event listener on the page (the component) would listen to the change event, and then run the appropriate code to create a modal with your content.