John, You need to upload it to your WordPress site in the media menu. Click ‘add new’ then click the ‘select file button. This will let you search your computer for the file you want to upload. It will then upload the file to your site. Once it has done this you need to go to your media library click view next to the image you want the URL for. It will bring up your site with the image. Click on the image and it will be in its own window the URL for this is image will be in the address bar.
Ivy