Following the next item in an array

I'm trying to make AI that looks for the closest checkpoint to the enemy and the player. Here is what I got so far -

 if(checkpoints.Length > 0){
 var nearcheck = checkpoints[0];
 var distance = Vector3.Distance(transform.position, checkpoints[0].transform.position);
 
         for(var i=0;i<checkpoints.Length;i++) {
             var tempdistance = Vector3.Distance(transform.position, checkpoints[i].transform.position);
             if(tempdistance < distance ) {
             if(tempdistance > 10){
                nearcheck = checkpoints[i];
                
             }
             }
         }
        
         var rotation = Quaternion.LookRotation(nearcheck.position - transform.position);
         transform.rotation = Quaternion.Slerp(transform.rotation, rotation, Time.deltaTime * 10);
          transform.Translate(Vector3.forward * 10 *Time.deltaTime);
          

But I'm stuck... How would I make it calculate the distance between the closest checkpoint to the ai and the player? And then follow the checkpoints in a series. Right now it's just spinning around the closest checkpoint to the AI. Thanks!