Welcome to the forums!
Since you are very new to budgies, it would be best to take your time in getting to know the species to become more acquainted with them by watching and interacting with your current budgie pair and to not yet had more budgies into the mix.
The decision to breed comes with a whole lot of responsibility and commitment, the lives of the breeding pair and the chicks are depending on you and the response you give if/when faced with adversity.
Things like being able to tell if your breeding pair is in good health and top physical condition to go through breeding; when a hen is expecting an egg or if she is showing the first signs of being egg bound; when a chick is having developmental problems, not being fed or showing signs of dehydration;
when there is aggression, abandonment and neglect of the chicks and it's solely up to you to feed and raise the chicks. The ability to detect early on and solve these issues can truly make a difference on the outcome of your breeding journey.
It's also not advisable to breed budgies in a colony setting by having multiple pairs sharing the same space, as this will add further stress on the budgie pairs and the end result can be tragic. Vicious fightings for a preferred nest can be triggered and this can lead to broken eggs, severely injured chicks/adults.
Talk Budgies has a wealth of information on this and on many other subjects and the pertinent info on the articles and sticky threads located at the top part of each sub forum will surely be very helpful to you.
Be sure to check these links below: