Scheduling form with several items that need to be rented at the same time

I need to make an appointment book:

• Scheduling information
• Sign multiple instruments at once with scheduling information

The Buscar cliente button pulls the data (Customer ID and Name) from a customer master table, as well as the buscar instrumento button that pulls only the Codigo instrument field from an instrument table.

Below the buscar instrumentos button has a dgv , in this dgv I wanted to put all the instruments that would be rented in a schedule, and then when I clicked the agendar button, and the% with% INSTRUMENTS RENTED would have dgvs of the dgv AGENDAMENTS and also would have all the fields that are inside the groupbox INSTRUMENTS TO RENT, remembering that the Insert button inserts the instruments in dgv of the group box INSTRUMENTS TO RENT and the delete button deletes the inserted instruments because the administrator has inserted some wrong instrument.

Form Code -----

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using UIWINDOWS.bdtccTableAdapters;

namespace UIWINDOWS
{
    public partial class FrmAgenda3 : Form
    {
        public FrmAgenda3()
        {
            InitializeComponent();
        }



        private void FrmAgenda3_Load(object sender, EventArgs e)
        {
            // TODO: This line of code loads data into the 'etecbd.Alugados' table. You can move, or remove it, as needed.
            this.alugadosTableAdapter2.Fill(this.etecbd.Alugados);
            // TODO: This line of code loads data into the 'etecbd.Agenda' table. You can move, or remove it, as needed.
            this.agendaTableAdapter2.Fill(this.etecbd.Agenda);


        }

        private void button1_Click(object sender, EventArgs e)
        {
            FrmBuscarMusico obj = new FrmBuscarMusico();
            obj.ShowDialog();
            iD_ClIENTETextBox.Text = obj.Codreto.ToString();
            nomeTextBox.Text = obj.Nomeretor.ToString();
            iD_ClIENTETextBox.Focus();


        }

        private void button2_Click(object sender, EventArgs e)
        {
            FrmBuscarInstrumento obj = new FrmBuscarInstrumento();
            obj.ShowDialog();
            codigo_instrumentoTextBox.Text = obj.Codret.ToString();           
            codigo_instrumentoTextBox.Focus();


        }
    }
}