WP has a built-in feature for making edits to your theme, named the Customizer. From customizer here you may change things like colors, background images, upload a logo and so on. Every theme will have different available options, and some commercial themes may not use it all in favor of their own custom options panel. All themes listed in the official WP directory have to use the Customizer, they are not allowed to use a custom options panel.This is to try to make the user experience the same for most themes.
To get started with the Customizer and see what changes you can make, for customize go to “Appearance” > “Customize” and it will load up. In the left-hand panel will be with all the available options, and on the right will be a preview of your site. As you make changes, they will be updated in real time in the preview.
You should check and review what options your chosen theme offers and have a test of them. Don’t worry about messing anything up, as nothing is added to your site until you click the “Save & Publish” button located at the top of the left-hand menu. After editing you can click on save button. your changes will be save.
