The moment you start, you begin to learn.
The first time you write about something you’ve never experienced, you’ll get it wrong. And the next. And the next. But this is only “wrong“ in the sense of “incorrect for someone else”, for no two people experience something in identical fashion. Sure, there are factual mistakes, of the historical or non-fictional breed - those are easily remedied with research and study. But experience is versatile.
If you cannot learn from your own experience, you can learn from that of another. An author does not need to empathize with his character; merely to sympathize with him, and to stir sympathy in the heart of the reader.
You may never write as well on the subject as someone who has experienced it themselves.
That in no way negates the need to write about it. A reader feels the deepest sense of keening and ownership when he can say, “I understand, I have been there, I have seen this, I have felt this.” Not all readers are authors; should they be derived of that experience, because he who held the pen didn’t dare venture into new territory?
We should always be educating ourselves. Learning more, seeking the new, wanting to grow and understand and experience.
If you would write on something you do not know, talk to those who have known it.