You don’t need to be a developer or even know anything about coding to use Markdown. It’s easy to learn and really only takes about a half hour to pickup.
Now that being said you don’t have to use Markdown to place images on a page. You should be able to to drag and drop the image from resources to a page. It would be helpful if you could tell us what type of page you are using? Styled text, Markdown or stacks might work a little differently. Also what exactly is happening when you try?
If you want to learn a bit more about images and Markdown check out this post: