Besides the official fight you will be sparring often. Even with headgear you can get knocked unconscious. So why wouldn't there be a chance for brain damage ?
The referees also watch closely and will give you a standing 8 count if you look like you got shook. They won't let you take punishment like some do in the pros.
That only happens to guys who are brawlers and get hit frequently and hard in the head, You'll be fine. Learn defense.
Depends on how unsharp you are of the game, and how well protected you are, and whether you were designed to take punishment or not.
I am very interested in boxing but I have heard all sorts of story's about how boxers develop brain damage and are never the same. What are the chances of an amateur boxer developing brain damage. It is not something I'd take super seriously just a hobby to keep me occupied