PHP 7+ OOP Class Library Review

I require a class library to facilitate some basic courier functions for a dispatch system. This is part of a coding challenge I am setting students.

Something very similar has already been done - https://github.com/panjezor/G4MDispatchSystem and I just need someone to basically review the code at this git, ensure it follows all coding best practice, naming conventions, etc. make changes where required.. such as the string class name, having multiple couriers.. etc. basically all of the issues encountered in the readme file, fixed.

I basically just need an hour of someones time to review and alter, rather than code from scratch.