There are 2 different ways to change the alignment of your picture, depending on the method you have used to add your picture to your website.
If you added your picture using the Picture widget:
1. Click Edit on the picture for which you want to change the alignment.
2. Under the Align section, click on one of the three options given to align your picture: left, center, right.
3. Save and update your site.
If you added your picture using the Text widget:
1. Click on the picture that you want to align.
2. On the Text Editing toolbar, you will see buttons for Align Left, Align Center, Align Right. Select the one that you want.
3. Save and update your site.