Connection to slow database

Question

I have a program in C# that when I start and ask to show me the data entered in Sql Server takes time to open, but after this time is already faster. There’s a way for the first time to be faster?

My connection is made this way and only stored use:

public class AcessoBaseDadosSqlServer
{
    private SqlConnection conexao()
    {
        return new SqlConnection(Settings.Default.StringConnection);
    }

    private SqlParameterCollection sqlParameterCollection = new SqlCommand().Parameters;

    public void LimparParametros()
    {
        sqlParameterCollection.Clear();
    }

    public void AdicionarParametros(string nomeParametro, object valorParametro)
    {
        sqlParameterCollection.Add(new SqlParameter(nomeParametro, valorParametro));
    }


    // INSERIR, ALTERAR E APAGAR
    public object ExecutarManipulacao(CommandType commandType, string nomeStoredProcedureOuTextoSQL)
    {
        try
        {
            // criar um ligação à base de dados
            SqlConnection sqlConnection = conexao();
            // abrir ligação
            sqlConnection.Open();
            //criar um comando
            SqlCommand sqlCommand = sqlConnection.CreateCommand();
            sqlCommand.CommandType = commandType;
            sqlCommand.CommandText = nomeStoredProcedureOuTextoSQL;
            sqlCommand.CommandTimeout = 7200;

            foreach (SqlParameter SqlParameter in sqlParameterCollection)
            {
                sqlCommand.Parameters.Add(new SqlParameter(SqlParameter.ParameterName, SqlParameter.Value));
            }

            return sqlCommand.ExecuteScalar();

        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message);
        }
    }

    // Consulta
    public DataTable ExecutarConsulta(CommandType commandType, string nomeStoredProcedureOuTextoSql)
    {
        try
        {
            SqlConnection sqlConnection = conexao();
            sqlConnection.Open();
            SqlCommand sqlCommand = sqlConnection.CreateCommand();
            sqlCommand.CommandType = commandType;
            sqlCommand.CommandText = nomeStoredProcedureOuTextoSql;
            sqlCommand.CommandTimeout = 7200;

            foreach (SqlParameter sqlParameter in sqlParameterCollection)
            {
                sqlCommand.Parameters.Add(new SqlParameter(sqlParameter.ParameterName, sqlParameter.Value));
            }

            SqlDataAdapter sqlDataAdapter = new SqlDataAdapter(sqlCommand);
            DataTable dataTable = new DataTable();
            sqlDataAdapter.Fill(dataTable);

            return dataTable;
        }
        catch (Exception)
        {

            throw;
        }
    }
}