First (while on your Post or Page Editor), click the TEXT tab on top of the Content Field (right next to the Visual tab).
Then click inside the top of the Content Text/Editor so the cursor shows up on the first line (where you add your text).
Next, click the “Add Media” button.
Select the image you want to use, and then look over to the right side where you’ll see “ATTACHMENT DISPLAY SETTINGS”.
Select the Alignment (in this case, select Right).
Choose an Image Size and whether you want it to link to something.
Now you can add your text right after the image…..unless you already have text. If you do already have text, just make sure it shows up after the image code.
Click the Visual Tab or view the Post to see if it shows up.
Let me know if that works.