Once you have opened a store on Amazon, you can start uploading and selling products immediately. Amazon does not force you to upload products within a specific time. However, in order to keep your store active and attract buyers, it is recommended to upload and list your products as soon as possible.

The time to list your products depends on many factors, including your inventory status, the progress of product preparation and optimization, and your sales strategy. Before uploading and listing your products, you may need to complete the following tasks:

1. Product preparation: Make sure your products meet Amazon's regulations and standards, including correct product information, clear pictures, accurate prices, etc. These preparations may take you some time.

2. Product list: List your product information one by one, including title, description, sales price, inventory quantity, etc. You can use spreadsheet tools such as Excel to manage and prepare large quantities of product information.

3. Image upload: Prepare clear, high-quality product pictures and upload them to your seller center according to Amazon's requirements.

4. Pricing and profit strategy: Determine your product pricing and sales strategy, taking into account factors such as cost, competitive environment and expected profit.

Once you have prepared your product information and completed the corresponding preparations, you can start uploading products and listing them on Amazon. Uploading and listing products in a timely manner will help increase your store's exposure and sales opportunities.