Center align the title and button

You’ll need to add some CSS to your theme, either with a child theme and CSS rules in a style.css file or with a plugin(Jetpack has a CSS addition feature). The best way to go about this is to tweak the CSS using your browser’s Inspect Tool.

If you’re not familiar with troubleshooting/tweaking CSS, this is a really good tutorial for testing changes in your browser:

http://bigemployee.com/4-simple-techniques-to-quickly-debug-and-fix-your-css-code-in-almost-any-browser/