WordPress Setup Checklist

Add backup plugin like Backup WordPress and set it up to take regular backup to a remote location such as Dropbox or Amazon S3.

Add a security plugin like Wordfence and set it up to block brute-force password attacks and enable firewall protection.

Add a caching plugin like WP Super Cache and turn on post and page caching to speed up the site for users.

Add a SEO plugin like Yoast SEO and set up Google and Bing Webmaster verifications, sitemaps and default title and meta settings.

Add a plugin like Akismet which can help block unwanted comment spam which otherwsie downgrade the quality of the site.

Analytics is essential to analyze the growth of the site and you can use a Google Analytics plugin or Jetpack analytics to collect metrics.

Make sure you have a way for your visitors to contact you for sending feedback and reporting site issues.

unoptimized images are the biggest reason for a slow site and a plugin like EWWW Optimizer can ensure that every image size is trimmed down.

Ensure your social profiles are present on the site and users have a way to share your posts and pages via Share Buttons.

Downtime can hurt your site badly thus having constant monitoring of your site via a service Like Jetpack Monitor or Uptime Robot is a must.