Can you access data from a database with pure react

Hi. I just have two questions relating to the ReactJS library:

1. Can you access a database (e.g. MongoDB) from purely with the ReactJS library (i.e. with no Express or NodeJS)?
2. I created a React Express app, however, after I created my landing page I wanted to add the main app page. How would I be able to do this since I'm pretty sure the ReactJS library only looks at the `index.js` file from the `src` folder. Also, if there is a way, is it also used best used for pagination?

Thanks.