Display proper error message in Signup form along with proper styling.

[Yash7426]

Currently, the Signup form lacks proper error handling and styling, which could lead to user confusion and a poor user experience.
This issue aims to enhance the Signup functionality by implementing clear and informative error messages for scenarios such as incorrect credentials or server errors.

Additionally, the styling of the error messages should be improved to ensure they are visually distinct and easy to understand.

To address this, contributors are encouraged to delve into the backend controllers to understand how to implement this feature seamlessly.

Remember to submit the screenshots/video along with the PR.