You'd go to Create>Upload Images, then upload the photo from your computer or device. You'd give you a title, alt-text (pleeeeaseeee give alt-text, that's very important) and as you type, it gives you the image code at the bottom.
Then you'd have your photo ready to paste into your entry. (I used a test image to make sure I got the right code - I also deleted some code to make sure it would show up in the comment.)
howdy!
It'll look something like this: < a href= https:// rattfan.dreamwidth.org/file/name here.jpg'> < img src = https:// rattfan.dreamwidth.org/file/100x100/name here.jpg' />< /a >
Then you'd have your photo ready to paste into your entry. (I used a test image to make sure I got the right code - I also deleted some code to make sure it would show up in the comment.)