As you would appreciate, these types of questions are being asked all the time on a forum like this The Ajahns may or may not answer directly here depending on their availability, but you should know that they have already answered similar questions and you can find their previous replies
As such it is a good idea to check if they have already been answered. This is easy to do by using the search function on the top menu
a search for not self produces the following results
You can narrow these down by adding the search terms of Sujato or Brahmali to the search terms.
A search for Nibbana yields the following results
Furthermore, there are extensive teachings in the audio visual category, and you can browse through that. Also it is very worthwhile to look through the resources in the essays category - there are many wonderful resources in here
If having read the material you have questions that haven’t been addressed, then you ask something more targeted.
I suggest this course of action, not from laziness in ‘providing the answer’, but because one needs to go through a gradual process of realisation before these deep insights can be realised.
Without this, ‘short answers’ like that of Paul, while they are correct, will not really ‘convince’ you. It is a process. It is an unrealistic expectation that you will penetrate some of the most profound questions of Buddhism without engaging in the process of the Noble 8 fold Path.
With much metta and best wishes for your journey of discovery