Most folks here (including myself) keep a Photobucket account (it's free) for such purposes as easily posting pictures here at CPYOA.
After you upload some of your pics there, each pic will have their own links. Tap or click the IMAGE link [IMG], for most browsers it will copy automatically (if not, do a control - C copy thingy), then just paste into your post or reply.
Get a pic or two up at photobucket and Practice some in the "test" area. If you still can't get it, someone here will fill in some detail that you or I missed.
Congratulations on your new(to you) CP27! I have a 19 so I don't deal with any through hull stuff,but I'm always reading about it for the day that might.