React.js Run Client Side JS After Render Finishes

I have a React app, but I need to run some client side js once the component has finished loading. What is the best way to run js that interacts with the DOM like $('div').mixItUp() once the render function has finished and loaded. Very new to React so sorry if this is stupidly easy.

Put your code inside the componentDidMount method on your component. See the documentation on lifecycle methods. With ES6 syntax, this will look like

class MyComponent extends React.Component {
    ...
    componentDidMount() {
        $('div').mixItUp();
    }
    ...
}