There is zero reliable ways to tell if there’s a rip from the beach…
The danger is under the waves, if there isn’t proper signage you won’t know until it’s probably too late. And everyone is different. The teens were able to swim to safety, the parents weren’t.
If you recognize you’re in a rip current, what you can try to do is swim parrell to the shore and then try to come in. It’s dangerous because the rip can’t be overcome by swimming directly in, you have to go around it.
But even if you know that, you might not remember, and it might not help.
The people that often die from this, are overconfident people like you who think it can’t happen to them because they’re smart.