Structuring C# Classes in Unity

using UnityEngine;

public class PlayerController : MonoBehaviour
{
    // 1. Serialized fields (Inspector-visible)
    [SerializeField] private float moveSpeed = 5f;
    [SerializeField] private float jumpForce = 8f;

    // 2. Private state
    private Rigidbody _rb;
    private bool _isGrounded;

    // 3. Unity lifecycle
    private void Awake()  { _rb = GetComponent<Rigidbody>(); }
    private void Update() { HandleInput(); }
    private void FixedUpdate() { ApplyMovement(); }

    // 4. Private helpers
    private void HandleInput() { /* ... */ }
    private void ApplyMovement() { /* ... */ }
}