To start selling on FB shop you first need to upload CSV on the catalog.

To Upload CSV,

1. Go to Facebook.com(https://www.facebook.com/)
   
2. Login the Facebook Account you wish to associate with the shop.
3. Now Create a Shop Page according to your requirements.
4. You will be redirected to this page:
   
5. Enter the name and category and get started.
6. Now go to the Product Page by visiting facebook.com/product(https://www.facebook.com/products)
7. The catalog is by default created in this section.
   
8. Choose the catalog you wish to edit by clicking on its name on the list.
9. You will be redirected to product data Source Page.
   
10. Click on the data source name of the product you wish to see.
11. Here you have all the information pertaining to the product.
    
12. If you don’t have a catalog then go to facebook.com/product (https://www.facebook.com/products). This page will show up and click on create catalogs:
    
13. Now choose the preferred category for your business and click on Next.
    
14. Now you will be redirected to a page – Configure your catalog category.
15. Select Upload Product Info.
16. Choose the Category and Name for your catalog and proceed.
17. A confirmation message will be shown stating a successful catalog creation.
    
18. Click on view catalog.
19. Now you will be redirected to this page.
    
20. Click on Product data sources.
21. A new page will open. Now click on Add Data Sources.
    
22. A page naming Add Product to your catalog opens up:
    
23. You have 3 options. Choose “Use data feeds”.
24. Here you can select how you want to upload.
    
25. You can either upload once–
    
26. Or you can schedule the upload at a later time:
    
27. Click on Start Upload and you are good to go.