Yes, you are right. "My friends are like" is correct. There may be some dialects of English where someone might use "be like" in some situations, so I don't want to say it's always wrong.

It's a modern piece of slang - it's good to know how it works, but it may go out of fashion very soon. It's not equivalent to "my friends are like..."; that is a statement of fact. "My friends be like [quote]" means that it's something your friends typically say. The subtext is that even though they may believe what they typically say, their behavior is usually the opposite. Interesting that the phrase uses present simple subjunctive - in a kind of way, this is extremely accurate grammar.