That's actually a great idea-- I always look at live action media for inspiration when I feel I need a little
variety
Animation gestures are fine to reference when you're learning the ropes, but after a while they can get a little samey, due to how the artform is taught and the limitations of its production. Meanwhile, two actors can go to the same schools and work on the same kinds of films, and still end up with radically different body language and unique mannerisms. You can get a lot of fresh stuff from quality movies and TV series.
But when you need something quick, there's always stock photos:
Just look up stock photos of everyday environments like school, work, and restaurants, and you'll find a treasure trove of ordinary gestures to choose from. Pro Tip: when you're drawing characters in these sorts of poses, focus on the arms and hands, rather than the face. "Everything expressions" are usually pretty neutral, sans the odd head tilt or eyebrow slant...the real points of interest are in the hands. Whether the character is resting their head in their hands, fiddling with something, pointing at someone: that's how you're going to express their personality and make them feel alive, even without any particular strong emotion.