Make use of
https://talkimg.com/. Upload the image there and paste it on your post. You can adjust the height and width.
Op is if newbies rank, so he can't add images to his post for now.. op, you need to be at least of a junior membership to enable images then upload to an image hosting site and post the link to display here on the forum.. or you can get a copper membership as well to enable you post images...