Right off the bat I will admit two things:
It's too small. But that's only partially because I ran out of time. The other "reason" is that each successive level is supposed to be larger (and more dangerous) than the one before it due to the shape of the hill.
The first few rooms of this were randomly generated using donjon.sh… but I have a good excuse! I was not prepared and it was my first time running AD&D as a DM so I had to think on my feet.
The Summary here is:
There's a Crumbling Monastery at the top of a hill in a relatively scrubby section of the forest. Merchants and travellers will occasionally stay here for temporary shelter for the night, but it's been abandoned for a long time.
There's a Stuck Door leading to a wine cellar with 3 still-good barrels of wine! Underneath one of them is an unlocked wooden trapdoor… which leads right into room #1.
The first level here only has 2 "permanent" monsters: tiny little spider lair, and the Badger. The Skeletons are 2 in 6 chance to be present, but the undead level is actually level 3. The Kobolds are your "hardcoded" first wandering monster check. Choose how many the party encounters based on what you think your party can handle.
If your party is making an egregious amount of noise, and showing no caution, I would make the next wandering monster check be something scary from level 4 which grabs one of them and carries him off to the garbage chute.
If the insta-gib pendulum trap is "too mean" for your taste, change it, but when I randomly generated that's the trap that was there, and my players got past it, so yours can too.
The "goal" of this dungeon level is really to have a nice score fairly hidden away, with hints of what monsters are on the lower levels: Kobolds wandering up here from level 2 and undead patrolling from level 3, with creepy crawlies from level 4.