This plugin renders particle js animations in the wordpress site. as shown here Particle JS Sample
Install this plugin by zipping the folder into upload plugin then activate it. Once activated place the below html to render the particle js in it
<!-- particles.js container -->
<div id="particles-js"></div>
visit particle js to generate the required effects. Once done come to the particle-background.js and edit the generated configurations. The new effects will show.
To change how the particle js canvas renders you can edit the css in particle-background.css. By default its designed to cover the entire page background using position: absolute and z-index: -1 for particlejs container and rest of elements use z-index:1 using * selector