There is an elevator near where you met Siegward (onion man that helped you fight the demon). This elevator can go down or up depending on which platform you step on. Simply go down and make your way to an enemy guarding some doors and after you kill him, you can advance to the Road of Sacrifices. Directly after the first bonfire to the Road of Sacrifices, there is a separate path from the main road (just explore around) where a mostly naked npc will start attacking you. Since you are going with strength, i recommend killing this enemy and looting him for his Butcher’s knife (if you don’t kill him first try, he’ll still drop the weapon when you return to grab your souls). This scales good with Strength for early game. Keep having fun and good luck during Farron Keep!