Themes controls the appearance of your WordPress site. There are thousands of free and paid WordPress themes available for every kind of website.
First, you will need to decide whether you want to use the free or premium theme. Premium WordPress themes come with support and guaranteed updates.
This does not mean that free WordPress themes are low quality. In fact, free WordPress themes that are available on WordPress.org theme directory go through a very rigorous review process.
You will also need to consider your audience, your website’s topics, compatibility with plugins, and language requirements.