company_Main.java

package com.company;

import java.util.Random;

public class Main {

    private static String[] teamNames, playerNames;

    public static void main(String[] args) {
        teamNames = new String[] {
            "Java FC",
            "Manchester United",
            "Arsenal",
            "Chelsea",
            "Liverpool"
        };

        playerNames = new String[] {"Async", "Jack", "William", "Robin", "Callum"};

        Team[] teams = generateTeams(5);

        for (Team t : teams) {
            System.out.println("Team Name: " + t.getName());

            for (Player p : t.getPlayers()) {
                System.out.println("Player Name: " + p.getName());
            }

            System.out.println();
        }
    }

    private static Team[] generateTeams(int amount) {
        Team[] teams = new Team[amount];
        Random rand = new Random();

        for (int i = 0; i < amount; i++) {
            String teamName = teamNames[rand.nextInt(teamNames.length)];
            Team t = new Team(teamName);
            Player[] players = new Player[11];

            for (int j = 0; j < 11; j++) {
                String playerName = playerNames[rand.nextInt(playerNames.length)];
                players[j] = new Player(playerName, t);
            }

            t.setPlayers(players);
            teams[i] = t;
        }

        return teams;
    }
}

company_Player.java

package com.company;

public class Player {

    private String name;
    private Team team;

    public Player(String name, Team team) {
        this.name = name;
        this.team = team;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Team getTeam() {
        return team;
    }

    public void setTeam(Team team) {
        this.team = team;
    }
}

company_Team.java

package com.company;

public class Team {
    private String name;
    private Player[] players;

    public Team(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Player[] getPlayers() {
        return players;
    }

    public void setPlayers(Player[] players) {
        if (players.length != 11) {
            System.out.println("Error message here");
            return;
        }

        this.players = players;
    }
}