Is your movetool selected: (Refer the below screen shot)
if yes, try to reset the tool.
Click on the drop down list on the right bottom of task bar in photoshop elements (refer the below screenshot)
Expand the drop down and select the option 'reset tool' (refer the below screenshot)
try to use the move tool again.
also, make sure your background layer is unlocked.
to unlock the Background layer, just double click on it.