Watch whatever series is popular
Be careful, doing shyt that's not you, just because everyone else is doing it isnt genuine. If you don't regularly watch TV, don't tune into game of thrones and queens gambit and Yellowstone cause everyone is watching it.
For shyt like that, that's when you use conversation skills and say
"I haven't watched, I'm not really familiar with it, tell me about it." This will get them talking to you. Then you follow up with "who's your favorite character?" Ask about the show try to build interest, get them talking about it. It could actually build into a real interest for you "is there an episode you'd recommend?" Then you watch it and report back to them...
The thing is, you have to pull at different strings otherwise every time y'all talk it'll be about that one show, or just shows in general.
It can't always be you pulling the strings, at some point y'all have to conversate enough to where the other person says something or asks something about you.