How does the Where logic in the Entity Framework work?

I'm studying C # and just did my first query in the Data Bank:

using System;
using System.Data.Entity.Core;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

    namespace Test.Models
    {
        [Table("usuarios")]
        public class Usuario
        {
            [Key]
            public int Id{ set; get; }

            public string Username {
                set;
                get;
            }

            public string Password {
                set;
                get;
            }

            public string Nome {
                set;
                get;
            }

        }
    }

In my Controller I do this:

var context = new SimpleContext ();

ViewBag.title = "Página inicial";

var usuarios = context.Usuarios
            .Where ((usuario) => usuario.Nome.Contains ("wallace"))
            .OrderBy((usuario) => usuario.Nome)
            .Take (10)
            .ToList ();

return View (usuarios);

I did not get to look at any tutorial, but I tried to make the query "in luck" and I ended up getting it.

I have understood so far that in the Where method it is expected to pass lambda . Another thing I understand is that the expression that returns true in there will be the data that will be returned from the table.

But here some doubts have arisen:

• Whenever I want to use Where , I just do something equivalent (that is, what I would do in Mysql , translating to C# ) within that lambda returning true or% how do I get the data I want to return?

• If I wanted users who did not have the word false , would it suffice to "deny" Wallace ?

• If Contains only needs a Where or true returned by false , how can lambda be able to use C # Syntax to query Entity Framework ?