I published a feature layer from ArcMap to ArcGIS Online but when I add it to a map and click on a feature, no information about the feature shows up. Did I miss a setting in creating the service?
Did you publish a hosted tile layer or a hosted feature layer? If this is a feature layer, ensure that pop ups are enabled in the web map (they should be by default). If you published a hosted tile layer without a feature service (contains the pop up information), Enable pop-ups on hosted tile layers without feature data (scroll down to this title).