Kerstin here from the Shopify Guru Team :)
When you are using multiple suppliers for your dropshipping business, then the items will arrive seperately. The best way of communicating this to your customers would be to write a really good copy - similar to how Amazon does it for example.
If all your products come from the same supplier, you could also arrange with him to bundle the products into one shipment only.
If you have any further questions, just reply to this thread or reach out to our support channels via chat, phone, or email.
All the best,