Do you think they maybe be a catfishes? How can I tell real women from fake?

So I met a few ''women'' on social media and I am wondering if they are catfishes. Most of them have one photo on their profile but send me one or two more when I message them. Some of them I tried to video chat with, however I haven't successfully video chatted with any of them because they either block themselves or say they have an old phone so they can't video chat. So how do I tell who's fake and who's a catfish?