[jimster]

I tried to insert image by copy and paste (nothing), by clicking insert image () and by click and drag. Apologies for being old and dense, probably missing the obvious.

Thanks in advance.

[Clyde Frog]

[img]http://link.to/your/image.png[/img]

If the image isn't already on the internet somewhere, you need to upload it somewhere first, like imgbb or someplace similar.

[Tumeni]

Or, to put it another way, you cannot directly upload images from your own computer or device.

As was said, you have to put them in a webpage, or on an image-specific  hosting site such as Imgur, Flickr, etc.