Full Code

package me.AcpSoldier7.Party;

import java.util.HashMap;

import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.event.Listener;
import org.bukkit.plugin.java.JavaPlugin;
import org.bukkit.scoreboard.DisplaySlot;
import org.bukkit.scoreboard.Objective;
import org.bukkit.scoreboard.Score;
import org.bukkit.scoreboard.Scoreboard;
import org.bukkit.scoreboard.ScoreboardManager;
import org.bukkit.scoreboard.Team;

public class PartyMain extends JavaPlugin implements CommandExecutor, Listener
{
    HashMap<Player, Player> invite = new HashMap<Player, Player>();
    HashMap<Player, String> party;
    {
        party = new HashMap<Player, String>();
    }
    public void addPartyMember(Player player, String value)
    {
        party.put(player, value);
    }
    public void clearParty()
    {
        party.clear();
    }
    public void removePlayer(String key)
    {
        party.remove(key);
    }

    public void onEnable()
    {
        getCommand("pa").setExecutor(this);
        getLogger().info("Party has been enabled!");

    }
    public void onDisable()
    {
        getLogger().info("Party has been disabled!");
    }
    @Override
    public boolean onCommand(CommandSender sender, Command command, String Label, String[] args)
    {

        String cmd = command.getName();
        Player player = (Player) sender;

        if(cmd.equalsIgnoreCase("pa"))
        {
            if (args.length == 0)
            {
                player.sendMessage(ChatColor.DARK_PURPLE +""+ ChatColor.BOLD +"Here is a list of the commands for party.");
                player.sendMessage(ChatColor.AQUA +""+ "pa deny -"+ChatColor.DARK_PURPLE+" Denies the party invitation sent to you");
                player.sendMessage(ChatColor.AQUA +""+ "pa accept -"+ChatColor.DARK_PURPLE+" Accepts the party invitation sent to you");
                player.sendMessage(ChatColor.AQUA +""+ "pa invite -"+ChatColor.DARK_PURPLE+" Invites the player you type to your party");
                player.sendMessage(ChatColor.AQUA +""+ "pa kick -"+ChatColor.DARK_PURPLE+" Kicks the player from your party");
                player.sendMessage(ChatColor.AQUA +""+ "pa leave -"+ChatColor.DARK_PURPLE+" Leaves your current party");
                player.sendMessage(ChatColor.AQUA +""+ "pa giveleader -"+ChatColor.DARK_PURPLE+" Gives the leadership to another member");
                player.sendMessage(ChatColor.AQUA +""+ "pa chat -"+ChatColor.DARK_PURPLE+" Turns the party chat on and off");
                return true;
            }
            else if(args.length == 2)
            {
                if(args[0].equalsIgnoreCase("invite"))
                {
                    Player TargetedPlayer = Bukkit.getServer().getPlayer(args[1]);
                    Player PartyLeader = (Player) sender;
                    if (TargetedPlayer!=null)
                    {
                        invite.put(PartyLeader, TargetedPlayer);
                        invite.get(PartyLeader).sendMessage(ChatColor.DARK_PURPLE+"[Party]"+ChatColor.AQUA +""+ ChatColor.BOLD +"Invitation sent.");
                        invite.get(TargetedPlayer).sendMessage(ChatColor.DARK_PURPLE+"[Party]"+ChatColor.AQUA +""+ ChatColor.BOLD +"You have been invited to join "+PartyLeader.getName()+"'s party."+ChatColor.DARK_PURPLE+" Type /pa accept to join.");;
                        return true;
                    }
                    else
                    {
                        player.sendMessage(ChatColor.DARK_PURPLE+"[Party]"+ChatColor.AQUA +""+ ChatColor.BOLD +"The player you tried to invite to your party is not online.");
                    }
                    return true;

                }
            }
            else if(args.length == 1)
            {
                if(args[0].equalsIgnoreCase("invite"))
                {
                    player.sendMessage(ChatColor.DARK_PURPLE+"[Party]"+ChatColor.AQUA +""+ ChatColor.BOLD +"Usage: /pa inv [player]");
                }
                if(args[0].equalsIgnoreCase("create"))
                {


                    player.sendMessage(ChatColor.DARK_PURPLE+"[Party]"+ChatColor.AQUA +""+ ChatColor.BOLD + "You have created a party. Use /pa invite to invite some players.");
                    ScoreboardManager manager = Bukkit.getScoreboardManager();
                    Scoreboard board = manager.getNewScoreboard();
                    Team party = board.registerNewTeam("Party");
                    party.setAllowFriendlyFire(false);

                    Objective objective = board.registerNewObjective("test", "health");
                    objective.setDisplaySlot(DisplaySlot.SIDEBAR);
                    objective.setDisplayName(ChatColor.GREEN +"Party Health:");

                    Score health = objective.getScore(player);
                    health.setScore(20);

                    party.addPlayer(player);
                    player.setScoreboard(board);
                    player.sendMessage(ChatColor.DARK_PURPLE+"[Party]"+ChatColor.AQUA +""+ ChatColor.BOLD + "Scoreboard created.");
                }
                if(args[0].equalsIgnoreCase("disband"))
                {
                    player.sendMessage(ChatColor.DARK_PURPLE+"[Party]"+ChatColor.AQUA +""+ ChatColor.BOLD + "Your party has been disband.");
                }
                if(args[0].equalsIgnoreCase("accept"))
                {
                    if (invite.containsKey(Bukkit.getServer().getPlayer(args[1])))
                    {

                    }
                    player.sendMessage(ChatColor.DARK_PURPLE+"[Party]"+ChatColor.AQUA +""+ ChatColor.BOLD + "Invitation accepted.");
                    player.sendMessage(ChatColor.DARK_PURPLE+"[Party]"+ChatColor.AQUA +""+ ChatColor.BOLD + "You don't have a pending invitation.");
                }
                if(args[0].equalsIgnoreCase("deny"))
                {
                    player.sendMessage(ChatColor.DARK_PURPLE+"[Party]"+ChatColor.AQUA +""+ ChatColor.BOLD + "Invitation denied.");
                }
            }
        }
        return true;
    }
}