Cadastro de Entidades do Projeto Web

Fiz todo o trajeto para a comunicação com o DAO e Controllers

No VendasDAO me surgem 5 erros

namespace LojaWeb.DAO
{
    public class VendasDAO
    {
        private object session;

        public void Adiciona(Venda venda)
        {
            ITransaction transacao = this.session.BeginTransaction();
            this.session.Save(venda);
            transacao.Commit();

Severity    Code    Description    Project    File    Line    Suppression State
Error    CS1061    'object' does not contain a definition for 'BeginTransaction' and no extension method 'BeginTransaction' accepting a first argument of type 'object' could be found (are you missing a using directive or an assembly reference?)    LojaWeb    A:\\Documents\Visual Studio 2015\Projects\LojaWeb\LojaWeb\DAO\VendasDAO.cs    16    Active

Severity    Code    Description    Project    File    Line    Suppression State
Error    CS1061    'object' does not contain a definition for 'Save' and no extension method 'Save' accepting a first argument of type 'object' could be found (are you missing a using directive or an assembly reference?)    LojaWeb    A:\\Documents\Visual Studio 2015\Projects\LojaWeb\LojaWeb\DAO\VendasDAO.cs    17    Active

e Mais três alertas surgem

Severity    Code    Description    Project    File    Line    Suppression State
Warning    CS0649    Field 'VendasDAO.session' is never assigned to, and will always have its default value null    LojaWeb    A:\\Documents\Visual Studio 2015\Projects\LojaWeb\LojaWeb\DAO\VendasDAO.cs    12    Active

Severity    Code    Description    Project    File    Line    Suppression State
Warning    CS0618    'DOMConfigurator' is obsolete: 'Use XmlConfigurator instead of DOMConfigurator'    LojaWeb    A:\\Documents\Visual Studio 2015\Projects\LojaWeb\LojaWeb\Global.asax.cs    19    Active

Severity    Code    Description    Project    File    Line    Suppression State
Warning    CS0618    'DOMConfigurator.Configure()' is obsolete: 'Use XmlConfigurator.Configure instead of DOMConfigurator.Configure'    LojaWeb    A:\\Documents\Visual Studio 2015\Projects\LojaWeb\LojaWeb\Global.asax.cs    19    Active