Many individuals and startups going on build their website and then forget about the little things like analytics and proper implementation of the tracking codes like Google Analytics, Google Tag Manager, Facebook Pixel, or LinkedIn Insights.
The obvious way is to paste the code in the Theme editor in WordPress where you can find the HTML and PHP files but this method could break your site, if not installed properly. Additionally, if you update your theme, there are chances that your theme files get updated which results in your tracking codes being deleted.
If you prefer setting up the tracking codes through the theme editor, you can follow my guide to installing GTM on WordPress.
About Google Site Kit Plugin
Google Site Kit Plugin allows a user to easily access their Google Analytics and Search Console dashboard directly on WordPress. It allays the fears to the cons of adding the tracking code directly to the theme files. The Google Site Kit plugin can be installed from the WordPress repository. Once the plugin is installed, with a simple Google sign-in you can link your Google Tag Manager. The rest of your tracking codes can be easily added to the Google Tag Manager.
Once linked to the Site Kit plugin, you can use the Tag Assistant extension on Chrome to check if the tracking codes are properly implemented on the website.
If you notice a drastic drop in your bounce rates or a bounce rate of almost zero, check for multiple instances of the installation of the tracking codes. This could be due to installations of the tracking code by multiple plugins like your SEO plugin or other header plugins.
If you found this article useful or have any other queries or suggestions, feel free to leave a comment or get in touch.