In order to achieve a smooth WMS implementation, you should create a product master that covers all your requirements and business flows.
There are 2 ways to import your product master: manual import using an excel spreadsheet or using an automated import from your marketplaces, website, or ERP system.
Regardless of which method you are going to use, I suggest preparing your product master in an excel file. This will give you a clear overview of all your products and their attributes.