In Present and Publish, you can hide and show legends from content item's context menu:
Alternatively, toggle an item's legend on and off using the Legend button in the Component ribbon:
To move a chart's legend, right click and select Open in Discover. In Discover, move the legend as required. The legend will automatically by updated in your presentation and publication:
Chart legends will be displayed in the content tree. To add a standalone legend, drag the legend item from the content tree onto the canvas. Resize the standalone legend as required.