VIllager Shop Creator (VSC for short). A great tool for Beginners to help learn and create custom villagers, not only is this a great pack to make shops but it will also teach you somethings about JSON text
Creating a Villager
When Creating a Villager, First place down a Lodestone Block and then spawn a villager using the Villager Spawn Egg
You have successfully created the Shop and now you will get a Book
Using the Book
once you receive the book, open it up to bring up the menu we will be using to make our Villager Shops

-[Change Rank]-Change the Level of the Selected Villager
-[Change Profession]-
Change the Profession of the Selected Villager
-[Change Biome Type]-
Change the appearance of the Selected Villager
-[Name & Extra]-
Change the Name, Silent, and held item of the Selected Villager
-[Add a Trade]-
Add a Single Trade to the Selected Villager using the Hopper, Switches to
-[Add a Chain Trade]-
Add a Chain Trade to the Selected Villager using the Barrel
-[Delete Recent Trade]-
Delete the last Recent Trade added to the Selected Villager
-[Extract]-
Extract the trades the current Selected Villager has into nbt tagged barrels
-[Reset Trades]-
Reset all trades of the Selected Villager and start from scratch
-[Save]-
Save and get Villager Spawn Egg with all the data of the Selected Villager
-[Delete]-
Delete the Selected Villager and it's Shop Workshop
Adding Trades

You can add trades in 2 ways, either using a hopper for single trades or a barrel for chain trades,
you can switch between them by pressing [Add Single Trade] or [Add Chain Trade]. make sure to follow the guidelines for adding your trades in
Multi Villager Shop at Once

You can have multiple Shops up at once, simply hit the villager to select it (this is will not effect his or surrounding villager's trades)
Changing Appearance & Name
You can have Villagers Hold and or Wear(on their heads) items!, I made it real simply and simply putting the desired item on your offhand (f) and selecting the option [Set Held Item] or [Set Head Item]
You can also change the Villager's Name by clicking [Get Rename Book]. it is in JSON text so if you have no clue how to use it, please click [Get Rename Manual]. I tried my best to easily explain it for you guys!once you put the custom name in the book, simply drop it onto the ground and the Selected Villager's name will be changed!IMPORTANT: DO NOT sign the Rename Book, it is made to be re-edited
Saving Your VillagerOnce you have chosen all your configs for the villager, simply hit the [Save] button on the first page of the book!You will receive an egg with the Villager's Data available for you to place anywhere in the world, and there you go! your new custom villager shop is ready to go!

+and i cant select villager sometimes
(villager)
(hopper)
/function shop_creator
And see if a list of commands show up
(And yes, a list of commands did show up when i typed the function command.)
Im going to see if i can give you a world download and see if that works, give me a few and I can get that ready