Connect React Frontend with Java Spring Boot Backend

### Description:

Integrate the React frontend with the Java Spring Boot backend to ensure seamless data flow and communication between the two layers. This involves setting up API calls in the frontend, configuring CORS if necessary, and ensuring both services are properly communicating.

**Tasks:**
1. **Frontend:**
- Set up API calls using Axios or Fetch for the following endpoints:
- Handle request/response cycles (display loading states, error handling).
- Update the frontend UI as per the responses from the backend.

2. **Backend:**
- Configure CORS in Spring Boot to allow frontend requests if they are hosted on a different domain or port.
- Ensure that the required endpoints (`GET`, `POST`, etc.) are properly set up and return the correct responses.

3. **Integration:**
- Test the API connection between frontend and backend.
- Ensure proper handling of errors and timeouts on both frontend and backend.