As to Anytime Dining - you go to the restaurant that handles that and ask to be seated as a party of 2 (or whatever number you are) or to join others. You might have a short wait depending on how busy they are. If you like the table and time and wait staff, you can request it for the balance of your cruise. Believe you can also call and make reservations. The other way to go is Traditional Dining where you are assigned either early or late seating and to a particular table which you have the entire trip.
As to a cabin in the bow, I can't really say as I've never had one. My personal preference is midships.