The other user wrote a very good list of cliché plot hooks, so I’ll write a few that are a bit less cliché but still pretty straightforward.

DEFEND THE VILLAGE: very easy and straightforward quests for people new to the game and people who want to chill for a bit and slay a few goblins.

• For the past few weeks, cattle have been disappearing every night, and a small town has been looking for courageous adventurers to find the cause. The clues lead to a nearby abandoned castle where a tribe of hungry kobolds has been squatting for the past few months. The castle, however, is the old fortress of a fallen order of paladins full of traps that have been laying dormant for decades, and that the kobolds have managed to get back up and running.
• In the middle of a snowstorm, the party crashes into a village that’s recently been attacked by quite the ferocious pack of wolves. The local hunter went missing looking for their nest, and the locals whisper of a fairy tale about the “Winter witch”. The party searches for clues and either finds out that the wolves’ alpha is a shapeshifter druid who may or may not be the hunter who disappeared a few days earlier (and the winter witch was just a red herring), or that the wolves are being charmed by a real and newly reborn witch that wants the village destroyed because of what they did to her a few centuries earlier.

FOR QUEST AND GLORY: for more adventurous parties who look forward to sailing into the unknown.

• In the middle of the forest, the party finds a few corpses of bandits and a lone, wounded knight. With her last breath, the knight tells the party that a conspiracy against the king is about to unfold, the details of which are in a sealed letter she has in her pocket. She pleas them to carry on her mission, and dies. Unfortunately, more bandits are on their tracks and won’t stop at nothing to destroy the content of the parchment.
• A drunk sailor, the last living member of his crew, talks of a cursed treasure. He begs the party to embark on a journey towards the nearby atoll and return the cursed amulet to its rightful place. The rightful place turns out to be the ancient necropolis of a Yuan-ti tribe who went extinct a few millennia prior to the events of the campaign, whose ghosts may be around still, or maybe the curse was made up, and there is another crew member who has assassinated all of his former companions to take all the treasure for themselves.

SHENANIGANS AND BOOZE: for chaotic parties and experienced DMs who can manage improvising on the spot.

• A downpour forces the party to seek shelter in an old monastery in the middle of nowhere. Shenanigans ensue in the middle of the night, as other people have the same idea. A few examples: a rich girl and her escort travelling north who turns out to be a pair of lovers running away from her rich father; a cutthroat mercenary looking for the aforementioned noblewoman; a wounded woman who turns out to be the local Robin Hood; a merchant who has lost his entire shipment to a pack of wolves and has unknowingly contracted lycanthropy; the friendly priest of the monastery who is actually an evil cultist intending to sacrifice everyone to his pagan gods.
• The Gods have deemed the mortals unworthy, and have thus decided that punishment is due. From dusk 'till dawn, the demons will be allowed to roam the land, exercising their powers as they deem fit, and they are intent on making the most out of the allotted time. One of them may be a lone hunter looking to infiltrate the town and kill everyone, or it may be a demonic general laying siege to the city with an army of ungodly monstrosities. The evil team may have multiple objectives which the party need to protect, such as: the church, protecting the icon of the only god who has refused to agree with the apocalypse; a family with a pregnant woman, who will give birth at the end of the day and whose smell has the demons riled up; an old crone, whose pagan magic is protecting the village; a wounded demon huntress currently resting in the village, who a few decades prior repelled the same demon that’s now attacking the village; a former cultist who has repented and has been hiding in the village for the past few years, who the demons want to make an example of.