Before you start to customize your WordPress theme, you must install the theme. In order to edit your theme, there are several options:
Method 01: Customizing Your WordPress Theme via the WordPress Admin Dashboard
If the improvements you want to make are design-related and simple, you may be able to do so through the admin panel. The Customizer provides you with a number of options for customizing your theme; the options available to you will vary depending on the theme. In the Appearance menu, you will notice something called the Editor.

Different themes provide different customization choices, but newer themes tend to be adding more and more of them on a regular basis.
Method 02: Customize via the Theme Editor
You can find a Theme Editor option in your admin screens, which you access through Appearance -> Theme Editor.

This gives you direct access to the files in your theme, allowing you to edit them.
If you want to make changes to your theme’s code, you should use a code editor (see our list of the best free HTML editors), and you shouldn’t make changes to your live site until you’ve checked it on a test site.
Method 03: UsePage Builders and Frameworks to Customize Your WordPress Theme
A large number of WordPress themes have customization options, which means you can alter the design and layout of the theme using the Customizer.
Some themes, on the other hand, go a step further and are designed to be expanded and heavily personalized. Those themes are called theme frameworks.
Using a Page Builder to Customize Your Theme
Page Builder plugins are designed to make it easier for you to customize the look of your website with an interface that shows you exactly what you’re getting.
Install a page builder plugin along with a compatible theme, and then use the options it provides to customize your site to your liking.
Elementor is one of the most well-known page builders, but there are some alternatives too.
Page builders allow you to edit your posts and pages using a drag-and-drop interface, allowing you to preview how your content will appear and customizing each page.
Using a Theme Framework to Customize Your Theme
Theme frameworks are an alternative to page builders. There are collections of themes that are meant to be used together. There is one parent theme, which serves as the framework, and many child themes in which you can modify the main theme and make it look the way you want.
An example of theme frameworks is Divi, which has customization options that let you tweak the design of your child theme even further, including a drag and drop interface similar to those of page builders.
Method 04: Editing Your WordPress Theme’s Code
If you’re comfortable editing CSS and/or PHP, you can customize your theme by editing the file. This provides you with the most flexibility.
If you’re editing your own theme, which is exclusive to your site and was built specifically for it, you can make changes directly to the theme. However, if you want to edit a third-party theme, you should build a child theme first to prevent removing your changes when the theme is updated.
What is your favourite way of editing the theme files?