cs8025 is a parsing error. In fact, your parenthesis are not always well-closed.
Functions (like Start and Update) ALWAYS have to exihibit parenthesis, even if they are empty or one-lined (they don’t have the same rule of if-conditions and loops).
Then, your FixedUpdate() is opened by two brackets.
Your class is completely mal-formed. See your updated class with comments
using UnityEngine;
using System.Collections;
public class player_not_walking : MonoBehaviour // <-- your class name contained a space :(
{ // <-- wrong curly brace, must open
public float speed = 50f;
public float jumpPower = 150f;
public bool grounded;
private Rigidbody2D rb2d;
// no opening and closing curly braces for the Start method
void Start ()
{
rb2d = gameObject.GetComponent<Rigidbody2D>();
}
// no opening and closing curly braces for Update method
void Update ()
{}
// This method was completely borked, the method name should be FixedUpdate not PixedUpdate, the arrangement of the curly braces was completely wrong.
void FixedUpdate()
{
float h = Input.GetAxis("Horizontal");
rb2d.AddForce ((Vector2.right * speed) * h);
} // <-- no closing curly brace for the FixedUpdate method... all depending on how you look at the inner scope you created, either way.
} // <-- missing closing curly brace