How to post data to entity framework database tabel?

Hello

I need some help post data to two tabels using entity framework. To explain this best as possible, I have two tabels (Booking and Passenger)

The Booking tabel has been created based on the current model:

public class Booking
    {
        public int Id { get; set; }
        public string BookingNumber { get; set; }
        public DateTime OutboundDate { get; set; }
        public DateTime ReturnDate { get; set; }
        public string Route { get; set; }
        public string ReturnRoute { get; set; }
        public string Passengers { get; set; }
        public string Pet { get; set; }
        public string VehicleType { get; set; }

        // Passengers
        public virtual ICollection<Passenger> PassengersList { get; set; }
    }

As you see, this is a booking and it can have a list of passenger (PassengersList) which is the second tabel and is based on this model:

public enum PassengerType
    {
        Adult, Children, Infant
    }

    public enum Title
    {
        Mr, Mrs
    }

    public class Passenger
    {
        public int Id { get; set; }
        public int BookingId { get; set; }
        public Title? Title { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public PassengerType? PassengerType { get; set; }
    }

Have created a bookingContext class which has the following methods:

        // DbSet to bookings
        public DbSet<Booking> Bookings { get; set; }
        public DbSet<Passenger> Passengers { get; set; }

Have made some dummy data using another class called BookingsInitializer. 

Can load all the bookings using the Bookings method in the BookingContext class which is working fine. Now I have an object which is fully updated based on user input, and I want to post the data on to the database.

I'm retrieving the current booking which should be changed by this line:

// Get booking from database
            var bookingFromDatabase = _db.Bookings.Find(booking.Id);

Now bookingFromDatabase is loaded and I can change it with the values I had from another object. How can i post these data back to the tabels?

Any suggestions? Also how can I check if the data has been loaded to the tabels succesfully? I guess with some sort of exception handling..

Hope someone can help me :)