By default, the About page under the Kosel theme is designed to display text to the left and an image to the right.
There is no need to worry about the page layout or HTML tags.
Try the following.
(1) Upload the image you'd like to display on your About page to the Library ('Library -> Upload').
(2) Create a new About page.
(3) In the 'Page Content' section of the About page, click the 'Browse Library' button (next to the 'Image Url' box) and select the image.
(4) Enter your text in the editor (there is no need to enter 'Source' mode or use any HTML tags).
(5) 'Save' the page and 'Publish' the site.
Hopefully this will give you the layout you are looking for.