public class Freelancer
{
    public int ID { get; set; }
    public string Email { get; set; }
    public string Password { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string CompanyName { get; set; }
    public string Avatar { get; set; }
    public Address FreelancerAddress { get; set; }
    public ICollection<Client> Clients { get; set; }
}

public class Address
{
    public int AddressId { get; set; }
    public string Street { get; set; }
    public string City { get; set; }
    public string State { get; set; }
    public string PostalCode { get; set; }
    public string Phone { get; set; }
    public string Email { get; set; }
}

public class Client
{
    public int ID { get; set; }
    public string Name { get; set; }
    public Address ClientAddress { get; set; }
    public string Logo { get; set; }
    public ICollection<Project> Projects { get; set; }
    public int FreelancerID { get; set; }
    public Freelancer Freelancer { get; set; }
}

public IEnumerable<Freelancer> Get()
    {
        var user = Uow.Freelancers.GetFreelancer(1);
        var result = from x in user
                     select new
                     {
                         ID = x.ID,
                         Name = x.LastName,
                         Address = x.FreelancerAddress.Street
                     };
        return result;
    }

[{"iD":1,"email":"david.stanley.13@gmail.com","password":"password","firstName":"David","lastName":"Stanley","companyName":null,"avatar":null,"freelancerAddress":null,"clients":null}]

public IEnumerable<Freelancer> GetFreelancer(int id)
    {
        IEnumerable<Freelancer> freelancer = (from x in DbSet
                         select x);
        return freelancer;
    }

IEnumerable<Freelancer> freelancer = from x in DbSet
                                     .Include("FreelancerAddress")
                                     .Include("Clients")
                                             where x.ID == id
                                             select x;

        return freelancer;

public class Client
{
    public int ID { get; set; }
    public string Name { get; set; }
    public Address ClientAddress { get; set; }
    public string Logo { get; set; }
    public ICollection<Project> Projects { get; set; }
    public int FreelancerID { get; set; }
}

public IEnumerable<Freelancer> GetFreelancer(int id)
{

    IEnumerable<Freelancer> freelancer = from x in DbSet.Freelancers
                                         .Include("Address")
                                         .Include("Client")
                                         where x.Id == id
                                         select x;

    return freelancer;
}