Shrink sidebar width

For that you’ll need to create a child theme and then change the required styles for those elements to suite your needs.

What’s coding skill level?

I can edit CSS and basic code. I have been playing with CSS but doing me no good so far.

OK cool.

Here’s a starting point for you – in your child theme’s style.css add the following CSS code. Note that this has already been adjusted from the original

.site-content {
	margin-right: 24.9999999975%;
}

.content-sidebar {
	margin-left: -24.9999999975%;
	width: 24.9999999975%;
}

@media screen and (min-width: 1008px) {
    .site-content {
		margin-right: 19.36507936%;
	}
    .content-sidebar {
		margin-left: -19.36507936%;
		width: 19.36507936%;
	}
}

Those are the values you need to adjust according to your needs – the affected areas will be the content area and the content sidebar. You’ll then need to adjust values for the featured image, content header, hentry and so on to suit your desired layout.

Hope that helps you get started.

Zulf