How can i design a database for my website using mongoDB

I just want..

Collection

• Signup
• admin
• products
• cart
• orders
• payments
• stocks

What is the better way to linked each other and optimized my database.

>Solution :

In mongoDB you have by Default ID. so you can use it to link collections each other.

• you do not need to make 2 collections for signup and admin.just add one field in single collection.

{
email,
password,
role
}

• Also you can set userID to cart and Payment collection to get particular user data.

Cart collection.
{
   itemname,
   itemID,
   price,
   userID
}

• Use can make payment and order collection like cart collection.
  Thank you!