Camera 2D Problems

Hi. I am currently working on a 2D Jump and Run and my Camera has got 2 problems

Problem 1:

When I start the game, my Character just flies around without me pressing anything.

Problem 2:

I added an 2nd Character but whenever I select it, The Camera doesn’t follow the 2nd Character, it just stays at the start.

The code is:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Camera2DFollow : MonoBehaviour
    public Transform target;
    public float damping = 1;
    public float lookAheadFactor = 3;
    public float lookAheadReturnSpeed = 0.5f;
    public float lookAheadMoveThreshold = 0.1f;

    private float m_OffsetZ;
    private Vector3 m_LastTargetPosition;
    private Vector3 m_CurrentVelocity;
    private Vector3 m_LookAheadPos;

    private void Start()
        m_LastTargetPosition = target.position;
        m_OffsetZ = (transform.position - target.position).z;
        transform.parent = null;

    private void Update()
        float xMoveDelta = (target.position - m_LastTargetPosition).x;
        bool updateLookAheadTarget = Mathf.Abs(xMoveDelta) > lookAheadMoveThreshold;

        if (updateLookAheadTarget)
            m_LookAheadPos = lookAheadFactor * Vector3.right * Mathf.Sign(xMoveDelta);

            m_LookAheadPos = Vector3.MoveTowards(m_LookAheadPos,, Time.deltaTime * lookAheadReturnSpeed);

        Vector3 aheadTargetPos = target.position + m_LookAheadPos + Vector3.forward * m_OffsetZ;
        Vector3 newPos = Vector3.SmoothDamp(transform.position, aheadTargetPos, ref m_CurrentVelocity, damping);
        transform.position = newPos;
        m_LastTargetPosition = target.position;


So its basically the standard Unity 2D Camera Code.
Can anyone help me with that one?