Thanks to those who sent suggestions re my inability to find the 'Edit" button on the new Blogger interface. I've now sorted it!
When I open my blog it always opens on the current page. On the old interface you would click 'new post' and then have all the tabs available to you to edit, comments, settings etc., but on the new one I need to go into 'Design' on the current page of my blog to access the edit function.
Not sure if that makes a scrap of sense to anyone but me!!! But I'm ok now!