Okay, I'll try, but I'm good with computer lingo, so someone may have to clarify.
First find a picture or gif you want to post. This is important, it must be from a Web hosting site, another words it has to come from a site that begins with http or www. Right click on the picture. I add it to "my favorites". When I'm ready to use it I go to" my favorites" on my computer and open the pic and right click the photo again. I then hit copy. This should save it.
Finally go to the message or thread you want to post it too. Then in the body of the post just below the message I hit CTRL V. You can also right click and hit paste. Here's one to practice on.
Go ahead. Right click the middle of the image and save to your favorites and follow the steps. Once you get it you'll find it's easy.
We'll get this one done then I'll help on you-tube, but I struggle with that one myself.