Login System created with C++

This is a Login System application created with C++. This project was created as a time killing project and it marked my first project that I did not have any help from teachers/tutorials at all. Though this project was written in C++, which is an Object Oriented Programming Language, I chose to go with traditional Procedural Programming approach from C. It was quite challenging, but also very helpful in terms of gaining experiences and debugging.
In order to use the project, please download all the files from project (.cpp and .h files if you're using any other IDE but Microsoft's Visual Studio) or clone it from GitHub. If you are using JetBrains CLion, please move the file db.txt into cmake-build-debug folder of the project to prevent bugs.
The program has internal instructions itself, with a menu of functions and error messages if an error occured during the run. I am open to any kind of feedbacks/comments/contributions. Hit me up with social media links above or through email preferably 😌