How to create a calculator for the game?

Question

Game development

There is a calculator for calculating equipment in the game I play "Warspear-online".
It is located at the link wsdb.xyz
But this calculator is no longer moderated, although it works.
In this regard, I have a request to explain schematically how to implement such a project yourself.
My experience in programming is at the 1st year college level.
I would like to write a similar calculator in the form of an application to use it offline
and replenish the database with new equipment.
The bottom line is that there is an object that has 4-6 variables and I can’t even imagine all this in my head and assemble at least a scheme for building an application. Still I am afraid to be mistaken in a choice of an implementation method.
Please tell me how to implement it simply and correctly Above there is a link this is an example of a calculator I would like to create such a local only