A beginner having trouble using maps

Good evening. I'm new to Roll20 as a DM. I was trying to set up a map (drag and drop an image from the marketplace) but when I do, there are no options when I right or left click, and, when I try to delete the image and start over, the same thing happens on the new page. When I drag my mouse across the image (map) I get the measuring tool. This happens in map overlay mode as well as the objects and tokens mode. What am I doing wrong? Thanks for your help. 

You are likely in the mode of using the map measuring tool - you need to select the manipulator tool in the left side of the screen - the stack of tools that shows an arrow, a cube, a brush, a lightning bolt... you need to select the top one. Then you can manipulate graphics on the desktop. This mode does not prohibit drag-and-drop from the right, which can make all of this confusing. 

The top box of the toolbar needs to be selected if you wish to move the asset around or be able to right click the art asset.

I'll give that a shot. Thanks for your help!