I've found some suggestions but I haven't been able to do what some people have done (for lack of programming skill).
On the thread below, I learned the CSS to make my pictures big:
However, I only want my pics big in my blog posts.
I removed the visibility of widgets in the third column only on "Pages that are Posts," via Jetpack.
Should I alter the post.php or singular.php files, make copies of them and put them in my Child theme folder?
The only thing I want is to make the pics in my blog bigger and no third column. I want to leave the front page alone.
My website is interior voyeur dot com.