Image left

Here is the paragraph associated with a left aligned image. It’s after the image.
Image centred
Here is a paragraph associated with a center aligned image. It’s before the image.

Here is another paragraph associated with a center aligned image. It’s after the image.
Right aligned image

Here’s a paragraph associated with a right aligned image. It’s after the image. You can confirm this using Block Navigation.
Here’s another paragraph associated with a right aligned image. It was created after the image was inserted and right aligned. It wraps around the image after a while. In the editor this happens a lot earlier than in the front end. Note: The image is thumbnail sized – 150px square. It takes many more words to get the text to go full width again.
Media and Text

Media and text paragraph with Normal font. You can’t choose the image size from a drop down. You just have to size it using the blue dot.