A noob needs help building a platform

Hello fellows,

since I'm pretty new to Unity and relatively new to coding, I want to try different things to improve my skills.
For my problem:

I want to write a script, that basically creates a flat square platform which should consist of 4 Vector3 variables. I already created a script that spawns cubes on a certain position but now I'm kind of lost and don't really know how to continue...
Can you maybe explain to me, what I can use in Unity to implement this idea?
You don't have to write some code for me, I just want to know which possibilites I have in that case.

Help is much appreciated.

Nik

 

https://docs.unity3d.com/ScriptReference/Mesh.html