How to create a plot system/data saving system similar to Retail Tycoon 2, and those other games

Hi, I was wondering if someone could point me in the right direction of a resource to learn how to set up a system that has the plots where you can place your own items, etc, and how to go about saving the players data of where they have their stuff placed on the plot, etc I’ve been trying to find resources but can’t really find much on how to create a system like this, that is a plot that you can expand in size by buying more land, and then decorating it, so if anyone has any resources on how to create it then save the players plot/data that would be great thank you. Also wondering if anyone has any good resources for learning how to save data thats more then just leaderstats, an example would kinda be like saving a players inventory of pets/armor/weapons that all have different stats, if anyone knows any good resources that would be greatly appreciated, again I’ve looked but can’t really find many good ones.