I don't even know how I was meant to go from there to 'netflix and chill'

If you don't have the social judgement to navigate this with grace and subtlety (and most young people don't, and many "rationalists" of any age don't), don't think about what you're meant to do, think about finding out what she wants to do. and don't overthink it or try to guess - admit your lack of knowledge so you can use your alternate skills in analysis, communication, and rationality. Tell her you're romantically inexperienced and really like her, but that you need help in understanding her pace and wants. If she's as awkward as you, this will turn into an adorable stammer-and-blushing festival where you end up with whatever level of chill you're both looking for. If she's less awkward than you, she'll let you know what's OK and what's not and you'll get there much more comfortably. If she tells you she doesn't want that, she just likes watching netflix, well, that's (probably) ok too.