I want that the enemies spawn in a random radius from the player, but not on other gameobjects like a housen or a car or something.

I have programmed a enemies spawner that spawns enemies in a random circle around the player. But the enemies keep spawning on other gameobjects like houses. Is there anyway to evoide that?

And here is my script:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class EnemySpawner : MonoBehaviour
{
    [SerializeField]
    public float spawnRadius = 7, time = 2.50f;
    public int Enemysnow = 0;
    public int enemyMax = 35;
    private bool maxreached = false; // Bool that stores the Information if the maximum is reached

    public GameObject[] enemies; //List of enemies that can get spawned

    // Start is called before the first frame update
    void Start()
    {
        StartCoroutine(SpawnEnemy()); //Start the Couroutine once at the start of the game
    }

    IEnumerator SpawnEnemy() // that is the important part
    {
        while (true)
        {
            if (!maxreached)
            {
                Vector2 spawnPos = GameObject.Find("Player").transform.position; //Spawning an enemy
                spawnPos += Random.insideUnitCircle.normalized * spawnRadius;

                Instantiate(enemies[Random.Range(0, enemies.Length)], spawnPos, Quaternion.identity);
                yield return new WaitForSeconds(time);
                Enemysnow++; // increase the enemy counter
            }
            yield return null;
        }
    }

    public void lowerMaxEnemys()
    {
        Enemysnow--; // decrease the enemy counter if a enemy is killed(Kill is in another script)
    }
    public void Update()
    {
            maxreached = Enemysnow >= enemyMax;
    }
    public void HigherMaxEnemys(int amount)
    {
        enemyMax += amount;
    }
    public void HigherSpawnRade(float amount)
    {
        time -= amount;
    }
}

I would solve it by checking if there is an object at the spawn location or not. Something like this:
if (!Physics.CheckSphere (spawnPos, size))
{
Instantiate(enemies[Random.Range(0, enemies.Length)], spawnPos, Quaternion.identity);
}