Please try by using small featured image, which will align featured image on left with content on right of blog post . For this
GO to dashsboard->basic setting-> Featured Image->Checked small featured image
To place featured image on single post you need to do customize content-single.php templates.
Note: If you are not technically sound on WordPress you need to take help from developer, As you need to to make some change on Html structure and coding too.
With our premium themes, we offer access to site documentation, video tutorials and timely support. Even if you have just started on WordPress, our support staff have the patience to help you create appealing sites gracefully.