What can i do?

using UnityEngine;
using System.Collections;

public class TransformFunctions : MonoBehaviour{

public float moveSpeed = 10f;
public float turnSpeed = 50f;

void Start()
{
        
}

void FixedUpdate()
{
    if (Input.GetKey(KeyCode.UpArrow))
        transform.Translate(Vector3.forward * moveSpeed * Time.deltaTime);

    if (Input.GetKey(KeyCode.DownArrow))
        transform.Translate(-Vector3.forward * moveSpeed * Time.deltaTime);

    if (Input.GetKey(KeyCode.LeftArrow))
        transform.Rotate(Vector3.up, -turnSpeed * Time.deltaTime);

    if (Input.GetKey(KeyCode.RightArrow))
        transform.Rotate(Vector3.up, turnSpeed * Time.deltaTime);
}

}
void OnTriggerEnter(Collider other)
{
if (other.gameObject.CompareTag(“Pick Up”))
{
other.gameObject.SetActive(false);
}
}
}/// CS1022

@Juancook
OnTriggerEnter() is outside the class and you have an extra ‘}’ at end.

Your code should look like:

using UnityEngine;
using System.Collections;

public class TransformFunctions : MonoBehaviour
{

     public float moveSpeed = 10f;
     public float turnSpeed = 50f;
       
     void Start()
     {
             
     }

     void FixedUpdate()
     {
         if (Input.GetKey(KeyCode.UpArrow))
             transform.Translate(Vector3.forward * moveSpeed * Time.deltaTime);

         if (Input.GetKey(KeyCode.DownArrow))
             transform.Translate(-Vector3.forward * moveSpeed * Time.deltaTime);

         if (Input.GetKey(KeyCode.LeftArrow))
             transform.Rotate(Vector3.up, -turnSpeed * Time.deltaTime);

         if (Input.GetKey(KeyCode.RightArrow))
             transform.Rotate(Vector3.up, turnSpeed * Time.deltaTime);
     }

    void OnTriggerEnter(Collider other)
    {
        if (other.gameObject.CompareTag("Pick Up"))
        {
            other.gameObject.SetActive(false);
        }
    }
}