How to implement a class to use PreparedStatement through it?

I have the following class Connects.java

package util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;

public class Conecta {
    //Pode ser alterado para Mysql...
    private String DRIVER = "com.mysql.jdbc.Driver";
    private String BD = "testes";
    private String URL = "jdbc:mysql://localhost:3306/"+BD;
    private String USERNAME = "root";
    private String PASSWORD = "";
    private Connection conexao;
    private Statement stm; //trocar por PreparedStatement

    private String msg;

    public Conecta() {
        this.msg = this.iniciaConexao();

    }

    public Conecta(String bd, String user, String senha) {
        this.BD = bd;
        this.USERNAME = user;
        this.PASSWORD = senha;
        this.msg = this.iniciaConexao();

    }

    public String iniciaConexao() {
        try {
            Class.forName(this.DRIVER);
            this.conexao = DriverManager.getConnection(URL, USERNAME, PASSWORD);
            // Definimos o objeto responsável por executar os comandos
            this.stm = this.getConexao().createStatement();
            return "sucesso";

        } catch (ClassNotFoundException e) {
            this.conexao = null;
            return "Não foi possivel encontrar o driver de banco: " + e.getMessage();
        } catch (SQLException e) {
            this.conexao = null;
            return "Erro!" + e.getMessage();
        }
    }

    public PreparedStatement getPS(String sql) {
        try {
            return this.getConexao().prepareStatement(sql);
        } catch (SQLException ex) {
            System.err.println("Erro: "+ex);
            return null;
        }
    }


    public String fechaConexao() {
        try {
            if (this.getConexao() != null) {
                this.getConexao().close();
                this.conexao = null;
            }
            if (this.getStm() != null) {
                this.stm = null;
            }
            return "Conexão Encerrada";
        } catch (SQLException ex) {
            return "Houve erro no fechamento da conexão! "+ex.getMessage();
        }
    }

    public Connection getConexao() {
        return conexao;
    }

    public Statement getStm() {
        return stm;
    }

    public String getMsg() {
        return msg;
    }


    public boolean insert(String sql) throws SQLException {

        this.stm = this.getConexao().prepareStatement(sql);


        return false;
        //Obter um statement
        //Statement stmt = con.getConection().createStatement();
        //executar o comando de Update seguido de um select
        //res = stmt.executeUpdate(sql);
    }

}

I need to initialize it in my main class to insert data into my database making use of the PreparedStatement, passing the parameters to the Connect.java class.

I'm trying to do as follows:

public static void main(String[] args) {

        try {
            Conecta c = new Conecta();


            String nomeCraque = "Coca";
            String sql = "insert into produto (nome) values (?)";

            c.getPS(sql).setString(1, "Cerveja");
            c.getPS(sql).execute();

            //DUUUUUUUVIDA AQUI, como executar?
            //PreparedStatement ps = c.getStm().execute(sql);
               // c.getStm().execute(sql);


            c.fechaConexao();


        } catch (Exception ex) {
            System.err.println("Erro:" + ex.getStackTrace());
        }
    }

They would help me solve this problem. What do I need to change in my classes?

If necessary, please provide more details.

Thank you in advance.