Is there an easy way to find a study object and add it to the study design?

Yes. You can use the Add To browser, which appears as a tab in the top right corner of the user interface by default, to search for and add study objects that are available, based on the study object you select in the Project Explorer. For example, if you select an item in the Project Explorer, codelists that are available to be added to that item appear in the Add To browser.