Relationship from Orders to Shop and Supplier, or to general User?
Following are my comments:


Users info should be isolated from Other Entities like shop, Supplier etc
Association between User and Shop should be moved to User_Shop table
Association between User and Supplier should be moved to User_Supplier table
There should be association between Shop and Supplier to view the Order from specific Shop by Supplier in the table Shop_Supplier.
There should be a table namely Order_Fulfil to map the orders fulfilled by Suppliers
Not sure about the mapping between the Product and User. Ideally there should be mapping between shop and product and order and Product.