Hey there,
One common practice is to build an API server and then use a library such as axios (github.com/axios/axios) to make requests to/from the API dynamically. This is often done through initializing state in your React component's constructor and then updating/setting the state in the componentDidMount() component function with your API call's results.
Here's a good example phrasing everything much better than me daveceddia.com/ajax-requests-in-react
There are several articles online that can quickly walk you through building a Node/Express API and connecting it to a db of your choice (Mongo, Postgres, MySQL).
A cursory glance at this one seems it'd be a good starting point. codementor.io/olatundegaruba/nodejs-restful-apis-…