Just as others have said, Bitcointalk is not a scam. It's a forum for discussing majorly about Bitcoin and crypto in general.
If your friend wants to avoid scammers of being scammed then they probability shouldn't go anywhere near the altcoin section. They should stick to the Bitcoin discussion section and learn whatever it is that they want to learn.
But if he decides that he wants to explore further then he should take note of projects that are offering rewards that are too good to be true and also he or she should try to learn how to research extensively about a project that way they can reduce the risk of them getting involved in a scam project. And they should never trust anyone online no matter what they may say.