Hey Peter

Thank you for posting in the Lucid Community. You should be able to delete a shape by single clicking the shape and pressing delete on the keyboard. Here's a short video that will show you the basics of a mind map that should help out along the way.

I would like to clarify--did you import data to create this mind map or did you create it from scratch? I would also like to know if you have used a template to create it or by using the shape library of mind map shapes. 

Hoping this helps--thank you for your help and patience as we get this sorted!