Given the fact your male budgie is not yet even at the very minimum required age to breed and your female is not showing any interest in him, it would be best to hold off on breeding.
By encouraging a young pair to breed who is not yet mentally mature for the task, you run much higher risks of having problems. The first one being premature clutch abandonment.
For now it really is best to remove the nest box or any other nesting sites from the cage and give more time for your budgies to grow and bond.
Wasn't your Pichi bullying Pollito not so long ago? Bugies who display a violent nature should not be put to breeding. This is a very serious matter, because the violence can heighten during breeding and the whole experience can very well end in tragedy.
In order to be better prepared, you should take the time to read the articles on breeding and the sticjy threads here at this section of Talk Budgies.
You can start with this one: https://talkbudgies.com/budgie-breedi...s-new-old.html
EDIT: From looking at your past posts, you don't seem to possess basic knowledge on the species nor have the required experience in budgie ownership in order to be able to fully assist a potential breeding pair and eggs/chicks.
Please refrain from breeding and learn as much as you can before making the decision to breed budgies in the future. Remember the very lives of the breeding pair and any chicks are depending on you and on your ability to properly care for them.