The important things you need to think about after you launched a new WordPress website should be improve the page loading speed, SEO, automatically backup and the security question, especially the latter two. Because I have paid for my lazy, many important data and files were lost before, that was my nightmare. Since then, I usually install and activate the following four essential plugins at the first time when I launch my new WordPress website, I hope it being recognised as serious, especially for the new WordPress users.
This is a very very amazing plugin that can automatically backup the entire WordPress website include mysql database. I usually use it with dropbox to sync all the data and files from dropbox to my local computer, it’s very easy to use. For how to do that, you can refer my previous guide ‘Use BackWPup plugin and Dropbox to backup your WordPress’.
Generally speaking, the free version of this plugin is enough for personal and small business website, of course if you need, just consider to buy the Pro version, more features included.
As WordPress is more and more popular, the security issue become progressively serious. Wordfence Security is NO.1 security plugin on WordPress.org, over 1 million active installs. You can use it scan your files, it will show you whether there are problems or not, and send email to the website administrator.
If your website is on enterprise level, they also provide premium version for you, learn more about the features of premium version here.
There are plenty of SEO plugins on WordPress.org, just recommend NO.1 SEO plugin: Yoast SEO. The reason I like this plugin is that it can automatically detect the post content and give me suggestions to optimize the keywords distribution, let me know the page SEO level is bad or good.
No doubt this plugin is the most powerful cache plugin can help you to speed up your website, however, there are too many options in the plugin admin page, maybe it’s a little difficult to get started for the junior WordPress users, just my personal feeling. The other cache plugin is easier and also a good choice, just check WP Super Cache.