any tips on how to beat the katana npc?

[SOLVED]

so i basically just started up DS3 and got to the firelink shrine and came across the katana dude who keeps butchering me. since i only played bloodborne before i'm having major problems with the parrying so if i could get some pointers on either the katana dude or how to parry better and get him that way i'd be really happy

thnx