Save and Load unity3d system

Hi, I try to save the user name that I get, from the input field pro and the player score and, I want to check if the current player’s score is higher than the previous player’s score, if it is, delete the name that had the lower score and keep the one with the higher score also is name, the same process if it’s not true in a JSON file using System.IO;
please, help me I stuck on this for a long period.
I don’t want to be insolent, but if you can please don’t make the code or explanation too complex(too hard to understand for starters) I started two months ago coding.

I created a script a few months back, for this question that saves a score, not a name, but if need be I can show you how to make one. (: