Take photos with your smartphone is the easiest way. Anything at all that interest you, take a picture. Then upload to google photos, but you must have a google account before you can do that. Then in Steemit submit story, click, select them. A box will open and you'll see your photos there. Click the photo that you like then click open. Watch the uploading percentage until it reaches 100%. Check the preview to make sure you uploaded it right. If you add another picture, go back to select them but make sure you push upwards the first photo by clicking the ënter".
I hope this might help. I know it's hard on the first time, but I'm sure you'll get it.