Bukkit tutorial commands | main class

package me.gamingod.BukkitCoding;

import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.event.Listener;
import org.bukkit.plugin.java.JavaPlugin;

public class Main extends JavaPlugin implements Listener {

    @Override
    public void onEnable() {
        Bukkit.getServer().getPluginManager().registerEvents(this, this);
    }

    //The Command
    public boolean onCommand(CommandSender sender, Command cmd, String commandLabel, String[] args) {

        //Checking if they are a player
        if (!(sender instanceof Player)) {
            sender.sendMessage(ChatColor.RED + "Only players can do this!");
            return true;
        }

        //If the command is /tutorial
        if (cmd.getName().equalsIgnoreCase("tutorial")) {
            Player p = (Player) sender;
            p.sendMessage(ChatColor.LIGHT_PURPLE + "" + ChatColor.BOLD + "IT WORKS!");
            p.setDisplayName(ChatColor.LIGHT_PURPLE + p.getName() + ChatColor.RESET);
            p.setPlayerListName(ChatColor.LIGHT_PURPLE + p.getName() + ChatColor.RESET);
        }

        //If the command is /commandtwo
        if (cmd.getName().equalsIgnoreCase("commandtwo")) {
            Player p = (Player) sender;

            //If there are no args
            if (args.length == 0) {
                p.sendMessage(ChatColor.RED + "Usage: /commandtwo <true|false>");

                //If there is one argument
            } else if (args.length == 1) {

                //If the command is /commandtwo true
                if (args[0].equalsIgnoreCase("true")) {
                    p.sendMessage("commandtwo is now a true");

                    //If the command is /comandtwo false
                } else if (args[0].equalsIgnoreCase("false")) {
                    p.sendMessage("commandtwo is now false");
                } else {

                    //If the command is /commandtwo <anything>
                    p.sendMessage(ChatColor.RED + "Usage: /commandtwo <true|false>");
                }
            } else {

                //Two or more arguments
                p.sendMessage(ChatColor.RED + "Usage: /commandtwo <true|false>");
            }
        }

        return true;
    }

}