Changing header on blog post

Hi, I’m seeing up my blog section and struggling with the single post page. I want it to look like every other page on the site. (see image) however, it’s been impossible to achieve. I can work out what to do. It currently looks like (see image)

Hope someone can help. The other headers are created in Muffin builder but even when i copied that it still looks wrong. I need it to be the default style and not have to redo each time I blog.

thanks for your time. Sheena

I also thought I could use just the builder or default template for each post however the menu and the titles are all mixed together. I can’t see where to change this. I’ve been going through the options. I can’t work out why.