Couldn't run the code here locally. ERR_CONNECTION_REFUSED

I cloned and made yarn install, and I am getting errors on the console for all the GETs and POSTs like:

```
Error: Network Error
    at createError (createError.js:16:1)
    at XMLHttpRequest.handleError (xhr.js:117:1)
    
    GET http://localhost:8080/api/tutorials net::ERR_CONNECTION_REFUSED
```