I'm only 19 and haven't really experienced much, so when people say 'write what you know' (wether or not that's sound advice i'm unsure), i fear that i don't know enough to be a screenwriter, as in i haven't lived enough, so i'm wondering what people's advice is to a young writer who is struggling with the idea of writing things i haven't experienced like falling in love etc. does it mean i'm not ready to be a writer, or should i just write in spite of not having much life experience?

I'm mainly interested in TV and it's the shows i've watched over and over which inspired me to start writing, i adore dark comedies and comedy dramas. i look up so highly to phoebe waller bridge, julia davis, richard gadd, michaela coel, sharon horgan, jack rooke, jamie demitriou and many more. i'd love to write stuff that does for others what those people's shows did for me, but how do you do that without copying? i suppose i'm genuinely asking how to avoid copying your inspirations.

some of the shows i love feel like they don't necesarily have a premise, a very loose one at that, and that they're so heavily character driven. i know that i want to explore characters and their relationships and i'm able to come up with those, but i struggle with the idea of a premise. because if you say you're going to write a comedy drama about someone navigating their twenties in a city, i imagine it's a bit 'eye roll, seen it before'. so how important is a premise, or can i find it along the way after i've made characters? and is a 'premise' as it were, necessary?