1.18+ has a glitch that disabled jigsaw blocks soooo no custom structures in 1.18 (but u should at least try, some structures replacing vanilla ones work if they are not too complicated)

I could fix this in a little bit. Thanks for letting me know about this!

I made commands not display in the chat so that when you clicked the buttons in the menu, it would be a seamless transition. However, this can easily be fixed by going into the load.mcfunction file. I have organized this file allowing you to see what specific lines do. Just go down to the gamerules section and you will find gamerule sendCommandFeedback false. If you delete this line, reload and set it to true, then it should work.

Sure! May not be the best explanation, but here you go:

Generation:
After a certain amount of time, a dungeon will spawn in a random location around the player along with a message that a dungeon has spawned. The very first room to spawn is the center room with four different paths. Each path has an entity on the righthand side of it. Beside this entity is a marked block like a cracked stone brick. If this block is on the north side, the structure will spawn a random room in the north direction. Likewise with all the other directions. The randomized rooms uses an Area Effect Cloud randomizer which spawns a set amount of Area Effect Cloud, and gives a tag to a random one. If the tag is given to AEC #1, it will spawn room #1. It will do this for every room. On spawn, it will create a raycast for every end point of a room. This raycast will find the size score and add to the placed size. Once the size matches or is greater than the set size, it will stop creating and then remove these entities that have built the dungeon.

Loot:
On top of each chest in the structure is an entity that puts loot in the chest. It will give the chest a loot table from this datapack, then remove itself.

Mobs:
Each custom mob in this datapack uses armor stands to display it. They are all basically slimes that do different damage values and look different. The code will look for these mobs and position the command at the position that the armor stand is set. It will then continually teleport the armor stand back into it's position. If one of these mobs is hit, the datapack will detect that and temporarily change the block that the armor stands are holding to better resemble a hit mob along with a sound effect built from mixed built-in sound effects. On death, it will search for the smaller slimes, and spawn a smaller version of that mob. The biggest one can be is the size of a full block (Falling Block). The smallest they can be is a small armor stand holding a block. For their drops, I added some loot tables to the slimes.

If you have any other things you'd like to know about this datapack, you can let me know and I will do my best to explain.