Grid System

I am really new to scripting and my friend and I are trying to make a sandbox mmo for us to have fun and learn as we go. We were talking about how we wanted to place down our houses and we came up with a grid system. I looked it up to see if anyone has done it before and found this vidoe! Would anyone have any idea on how I would start making something like this?

Thank you so much for your time =)

You start here

I have been watching other tutorials and I understand the basics. I just cant find any tutorials or anything to learn how to do something like this. That’s why i looked here