Problems retrieving DB data with Entity 6.1.3 and Web API

I did a test project, called quotation to use the Web API and Entity. Well, I've been to my web.config and created my connection string like this:

<add name="CotacaoContext" connectionString="Data Source=Minha_Maquina\Instancia; Initial Catalog=Cotacao; User Id=sa; Password=d123" providerName="System.Data.SqlClient" />

This provider is there, because before I had made a mistake of his lack, so I put it. In my controller I have made a method to get the users of the DB and it is giving a stick. This is my method in Controller (all code).

public class UsuarioController : ApiController
    {
        private CotacaoContext contexto = new CotacaoContext("CotacaoContext");

        [AcceptVerbs("Get")]
        public IEnumerable<Usuarios> GetUsuarios()
        {
            return contexto.Usuario.AsEnumerable();
        }

        public Usuarios GetUsuarioById(int id)
        {
            Usuarios usuario = contexto.Usuario.Find(id);
            if(usuario == null)
            {
                throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotFound));
            }

            return usuario;
        }

        protected override void Dispose(bool disposing)
        {
            contexto.Dispose();
            base.Dispose(disposing);
        }
    }

This is my Context class that will create the DbSets and connect to the database.

public class CotacaoContext : DbContext
    {
        public CotacaoContext(string connectionString)
            : base(connectionString)
        {

        }
        public DbSet<Usuarios> Usuario { get; set; }
        public DbSet<Login> Login { get; set; }
    }

And this is my model that abstracts the table from the database.

public class Usuarios
    {
        public int Id { get; set; }
        public int Tipo_Usuario { get; set; }
        public string NMUsuario { get; set; }
        public string Senha { get; set; }
    }

An important note. There is 6 record in the table that I put in the hand, and there is a table that does a foreign key in the user table, but since I am testing the connection first, I have not put it in my model yet. Below is a print at the time of the debug.

SeethatwhenIputthemouseinthecontextvariable,6itemsappear,butwithaquestionmark(mytablehas6records).Ihavebeensincelastnightontheinternet,totrytofindoutwhy,butlackalittlemoreknowledge(that'swhatI'mlookingfor).I'mwaiting.

Edit1-Animportantpoint.Theattribute[AcceptVerbs("Get")] I put later, in the attempt to hit.

Edit2 - There came a light. Do I need to do anything in the api web routes file?

Edit3 - When I run both in the browser and in Postman, this is the result: []