Welcome to the forums!
You have a gorgeous pair, however from those pictures I can see your male budgie is still very young (has the immature purple colour on his cere) and the female is also not in breeding condition.
The bare minimum age to allow budgies to breed is 1 year old, your budgies are still young to be put up to the task so I advise you to remove the nest box and to not give them anything that they could use as a nest.
This will also give you more time to prepare, getting to know your budgies and working on bonding with them. By establishing a good bond with your pair you will also build the foundations of trust and this will be very important during breeding when you need to check the eggs/chicks and clean the nest box.
If you haven't done so already, check the info on the stickies at the Diet and Nutrition, Training and Bonding and Budgie Breeding section of the forums.