Need Help with multiplayer

So i followed a tutorial on how to make high lvl network. but i still dont understand how to enter character selection first when 2 players r ready and each one chose a character to start level

This is very little info.
What tutorial did you follow?
Show us the relevant code.

i did follow Godot Multiplayer Tutorial: The Quick and Easy High-Level API

also heres some of codes

# for server UI code 
extends Control


func _on_server_pressed():
	HighLevelNetwork.start_server()


func _on_client_pressed():
	HighLevelNetwork.start_client()


# for spawner
extends MultiplayerSpawner

@export var network_player: PackedScene



func _ready() -> void:
	multiplayer.peer_connected.connect(spawn_player)



func spawn_player(id: int) -> void:
	if !multiplayer.is_server(): return
	
	var player: Node = network_player.instantiate()
	player.name = str(id)

	get_node(spawn_path).call_deferred("add_child", player)
# for player to enter tree 
extends CharacterBody2D


const SPEED = 300.0
func _enter_tree() -> void:
	set_multiplayer_authority(name.to_int())

func _physics_process(delta: float) -> void:
	if !is_multiplayer_authority(): return
	velocity = Input.get_vector("ui_left", "ui_right" , "ui_up", "ui_down") * SPEED
	move_and_slide()