Creating an enemy when a random value = 1

I have been working on a basic wandering enemy AI. I have set up the variables I need, but the way it is deciding whether or not it should spawn returns the errors “Invalid token ‘=’ in class, struct, or interface member declaration”, “Invalid token ‘(’ in class, struct, or interface member declaration”, and “Invalid token ‘)’ in class, struct, or interface member declaration” on line 18 of my code.

Here is the code(C#)

using UnityEngine;
using System.Collections;
public class OverworldWalk : MonoBehaviour {
public float ChanceToSpawn;
public float WalkSpeed;
public float EncounterRange;
public float DespawnRange;
public float SpawnRange;
public Animation WalkAnimation;
public Animation IdleAnimation;
public GameObject Player;
public GameObject Enemy;
public float X;
public float Y;
public float Z;
public int Spawn;}
public class CreateEnemy : MonoBehaviour {
Spawn = Random.Range(1f, ChanceToSpawn);
	void Start() {
		if (Spawn = 1)
			Instantiate (Enemy);	
}}

I’m sorry if my code is hard to understand, or is this is a very simple answer, but how do I tell unity that lines 18-22

public class CreateEnemy : MonoBehaviour { ////// line 17
Spawn = Random.Range(1f, ChanceToSpawn); ////// line 18
	void Start() { ////// line 19
		if (Spawn = 1) ////// line 20
			Instantiate (Enemy);	 ////// line 21
}} ////// line 22

How do I tell unity lines 18-22 are not a class, structure or interface member?

Thanks in advance, sorry for disorganized code.

if (Spawn = 1)

You have an assignment in a condition:

 if(Spawn == 1)

you need two of them.

A single equal sign is an assignment, double equal sign is a comparison.

if (Spawn = 1) should be if (Spawn == 1)

Secondly, there should not be 2 MonoBehaviours in the same script. They should be in their own respectable seperate scripts. You’ll need to redesign a bit, because how is CreateEnemy supposed to have access to Spawn, when Spawn is declared in OverworldWalk?

Also, Spawn = Random.Range(1f, ChanceToSpawn); needs to be inside of a function.