Hi @nicku92 you need to click "submit a story" or "edit", search for an image, copy the url and paste it in the post wherever you want it to be.
Other two options for non-internet images are opening Steemit at your cellphone and press "upload" to directly upload an image from your cellphone to Steemit (I did this at my latest post), or you can upload the image to an external server like imgur.com and copy/paste the link here in your post.
I hoped I was being helpful enough! If you still have doubts, don't hesitate to ask me everything you need
you are a baller, thank you for the assistance. the issue was happening on my cellphone via the steemit app
You can try it directly on Google Chrome at you cellphone too. That's what I do when the app is bugged