How do I control objects created by a class

Hello, I have a beginner question!

I am designing my own particle system in Unity. So far I have a particle class which defines the particles location, size and age. I also have an emitter class which has a data structure for the particles.

I do not understand how to control game objects that are not already attached to a game object. For example my particle class is defined as:

 public class Particle : MonoBehaviour {
     
     public int position,
                 velocity,
                 age,
                 maxAge;
     GameObject appearance = GameObject.CreatePrimitive(PrimitiveType.Sphere);
                 

and my emitter class is defined as:

public class Emitter : MonoBehaviour {

     //setup data structure to hold particles
     Particle[] p_system = new Particle [500];
     
     // Use this for initialization
     void Start () {
     
         //initialize all of the particles
         for(int i = 0;i < p_system.Length;++i)
               p_system[i] = new Particle();
     }

On Play, I'm able to spawn 500 spheres, but I do not know how to edit their transforms.