Anders from the Shopify Social Care team here. Thanks for reaching out today!
If you're looking to bulk export information from your orders, like tracking numbers, the easiest way to do this would be by using the Order Printer app and a customized template to include an order's tracking number.
Essentially, the app allows you to bulk print order details into invoices or packing slips. However, the template for these invoices can be modified to include order information like tracking numbers. Potentially, you can either create a new template to only pull the tracking number, or you can customize one of the existing templates (invoice or packing slips) to also include the tracking number information. While HTML or Liquid knowledge will be required to customize a template, if you're not sure how to make these changes, feel free to follow back up and I can put in a request to our Theme Support on your behalf.
Our app, EZ Exporter, can bulk export the tracking numbers for you as well. You can export them both on the order level and the line item level (in case there are multiple fulfillments, you can see which tracking numbers are associated with each line item).
Please feel free to reach out if you have any questions!
Instead of generating shipping label externally and importing the tracking numbers in bulk using CSV, I recommend you to check out the Shopify Multi Carrier Shipping Label app, which will help you to integrate directly with carrier account to generate the shipping label and send the live tracking to customers.
You can easily handle 100s of orders everyday using the app. With just a single click, you can generate shipping labels for all your orders and the tracking number for these orders will be sent to the Shopify order details, which is then sent to the customers via email.