Hair styling and cut advice

hello LBWT! I'm (hopefully) going to be an incoming 1L this fall and I need some advice on how to manage my hair. I have long (hits my waist when in the back of my head), fine, pin straight, and layered hair. my hair tends to get stringy throughout the day, even when it's styled, it's also incredibly greasy on the root so I have to wash it everyday. my mom worked in a conservative professional environment years ago and thinks my length needs to be shortened in order to look more professional (but I really can't bear to part with my long hair!). my big questions are: is long hair frowned upon in conservative jurisdictions? is unstyled hair unacceptable and if so, does anyone who washes their hair daily have tips on how to easily and time efficiently style it every night? and lastly, what hairstyles are the fine haired girls wearing to avoid stringy hair? tysm!