Jerk, Lag When Moving Object 2D

Unity Engine
1

First sorry my english just translate using google.
I learn Unity in 2 months.Now, I making 2d runner endless game.When i moving objects (Background, Character…) occur jerky lag on screen.I don’t know how to solved it.
here my code :
i used :

transform.Translate(Vector3.left*speed*Time.deltaTime);

and :

transform.position =  Vector3.Lerp(transform.position,
new Vector3(transform.x - 500f,transform.position.y,0),Time.deltaTime);

i try it at funciton Update(),FixUpdate(),LateUpdate() but same result.
i try change Time.deltaTime with constant number => same result.
i try change Time.detaTime = Time.smoothDeltaTime => same result.
i try change Time.detaTime = Time.fixedDeltaTime => same result.
i try set Time.maximumDeltaTime = 0.00001f => same result.

i used iTween, DOTween but same result.

please help me !

2

How many Objects are you using this on because When i had 20 mobs all with
//FAKE CODE
void update()
{
targetposition = new vector3(x,y,z);
transform.position = Vector3.MoveTowards(transform.position,targetposition , step);

}

being done during update my game lagged like crazy.
I changed it to This and I could have like 200 mobs with updating positions with minimal lag

//FAKE CODE
void start
{
//creates one new vector
TargetPosition = new Vector 3 (x,y,z)
}

void update
{

//updates the vectors xyz manually IDK but this change removed my lag
TargetPosition.x = “insert x calculation”;
TargetPosition.y = “insert y calculation”;
TargetPosition.z = “insert z calculation”;
transform.position = Vector3.MoveTowards(transform.position,targetposition , step);

}