Now, all that being said, one of my favorite 1st session hooks is a variation of the maiden in distress at the tavern.
I like to begin the campaign with my party already together. I hate the awkward first hour of people stumbling through meeting and trusting each other, etc etc. It's like spending an hour before monopoly negotiating about the money and the game pieces.
So I like to start with the PCs having just completed some basic starter adventure already. Caravan escort, etc. They're celebrating their adventure when a forlorn farmer's daughter enters the tavern. She needs help but has very little coin to offer. The grizzled veterans at the bar ignore her. She finally approaches the group.
She desperate for help. She lives on a farm with her aunt, uncle and cousins a few miles out of town. They've been plagued by kobolds lately. She came to town to sell corn and wheat flour at the market and when she arrived home, she discovered that all of her relatives missing. The door was battered down. There is blood splattered on the porch and floor. She came back to town for help. The town watch refused to aid them because it's out of their jurisdiction.
She desperately needs help of willing, good folk. She has almost no coin or anything of value to offer. She's certain her uncle will reward them with food and hospitality. Her uncle was once an adventurer himself and she's heard her cousins talk about a magic sword hidden in the wine cellar.
If the party decides to go with her, they find the farm just as she described it. It's pitch black. No lights. Scarecrows in the field. Front door battered down. Horses and cattle can be heard in the barn. There's a trail of blood and trampled glass leading to the barn. Blood is definitely fresh. The wine cellar is beneath the barn. They must have come for Uncle's magic sword!
Once in the barn, there is a tool room with a locked door at the back of the barn. The lock has been bashed in. The horses and cattle are freaking out. One of the cattle has been slaughtered (if investigated, the wounds inflicted denote ritual wounds. Religion check - markings match ritual of a death cult).
If they go into the tool room, there is a trap door. The trap door is open. Ladder down into a wine cellar. Blood on the ladder. Blood pool on the floor. The eastern wall is collapses, leading to a cave. The magic sword is missing.
The maiden goes last. Cave leads to a large, round chamber lit with candles and occult symbols. At the far end of the chamber wall, there is a stone dias with 3 sarcophagi.
There is a deep rectangular pool of dirty, dark water in the center of the chamber. There is a winch and pulley system with chains going down into the water. There are 6 stone pillars flanking the rectangular pool: 2 on the left, 2 on the right, 2 behind, facing the party. There is an elderly man and elderly woman bound to the two pillars on the left. They bound to the stone pillars by some kind of cocoon which looks like a yellowish fluid that has hardened, like glass. Only their heads are free of the cocoon. They are unconscious.
The maiden cries out, "Uncle Marsimus!! Aunt Jollie!!" and runs to the cocoons. She begins to claw at the cocoons with her nails, uselessly.
As soon as any of the party gets within arms reach of the maiden, she lets out an unearthly howl. Two of the three shoddy wooden sarcophagi open. Two Hags emerged.
Maiden turns to face the party. She is a Hag as well.
It's a trap!
The Hags are only trying to incapacitate the party. They will KO only when a PC reaches 0 HP.
If the PCs beat the Hags, there is loot and some weapons in the chamber. Since the PCs were teased with a magic sword, you should include some sort of magic items.
The yellow-mucous cocoons can be destroyed. Need to beat DEX 10 check to keep from harming the person in the cocoon. 10 HP. Vulnerable to Cold attacks, Resistant to Fire attacks.
If the PCs raise the winch an pulley, a metal grate platform rises from the cold, dirty water. There are 6 glass containers about the size of the a human head. When the grate rises, each container is in front of each pillar about chest level of people on the pillars.
The two containers in front of the elderly man and woman are missing their lids. They are full of smelly, funky grey water and a shriveled pod. The other 4 containers still have lids on them. They cannot see what's in them because the water is filthy without opening the lid or backlighting the container with a bright source of light. The containers each have a football-size pale, fleshy pod in them. A DC 15 Nature check will determine that the pods are Slaadi parasites.
The Hags are luring naive adventures to the farm, binding them to the pillars and impregnating the people with Slaadi tadpoles. They sell the infected hosts to villains to grow and raise Slaadi. It's a Slaadi farm.
The man and woman will experience Slaadi chust-bursting in 1d4 hours from the moment they PCs find them.
If the players cannot handle the Hags and attempt to retreat to the wine cellar, they discover the trap door is locked from the inside. Maiden locked it (it's why was the last person to come down the ladder). If someone is watching her when they enter (they need to beat a 15 DC Perception check vs her Sleight of Hand.
Lock is a DC 12 lock to pick. Trap Door is DC 12 to bash, but at Disadvantage because they're doing it from a ladder.
There is another exit out of the cellar the PCs didn't see as they came in on the other side of the wine racks. A stairway up to the exterior of the barn (like a storm cellar), a tunnel that leads back to the house (a bolt hole). It can be a secret door if you like, but the idea is that the PCs do not get completely trapped if they cannot handle the Hags.
If they make it outside and any Hag has survived and chases them, they will animate 1 or 2 of the Scarecrows in the fallow fields (depending on how banged up your PCs). That's what the cow slaughtering ritual they discovered earlier did.
Stat blocks on the MM: Slaadi Tadpole, p. 276. Hags, p 177. Scarecrow p. 268.
Now, the CR for this adventure for level 1 players is Lethal. The CR for the weakest Hag (Green Hag) is 3. So three Hags would decimate a level 1 party. I highly recommend re-skinning the Cultist (MM p. 345) with basic Hag abilities. Or for a larger party, Cult Fanatics (also MM p. 345).
Highly recommend using clues and items in the Chamber loot or in the farmhouse to tie the adventure into your over-arching story: tie it in with your character origins, the Cult of Death plays into the story later on, the villains of the region are pissed that their supply of Slaadi has been cut off, etc.