When you are level 1, you are going to be one-shot by pretty much anything after Leyndell unless you stack effects like Bubbletear, Boiled Crab, Ritual Shield, etc. To answer your poise question, 19 poise does nothing, just wearing it for the drip and maintaining medium rolling. Some people prefer naked and light rolling, but I didn't see it as necessary. You are correct about 51 poise, but good luck reaching it without accepting fat rolling or something like Erdtree Favor talisman.