How to change google search results title for my site using HTML tags?

How would I change the title of my website when it appears on Google search results?

There are three different tags for title so not sure which one to use?

<title>example title</title>

<meta property="og:site_name" content="example title" />

<meta property="og:title" content="example title" />

I'm using weebly to create my site, I can change the title of the entire website and also the title of each individual page but I want my google search result for my homepage to read "example 1 - short statement"

<title>example 1 - short statement</title> 

Use this to display your main title. It should be placed at your index so that your homepage will end up like this.

You can verify if its working by looking at the tabs in your webbrowser, whether does it reflects what you want to be shown in your google search results.

This guide: https://moz.com/learn/seo/title-tag will help you learn more and play around with this .