Full Question
Can I design my own product? What will be the minimum order for my own design product? And how do I send the design to the manufacturer?

Answer
Can I design my own product?

Certainly. But not all suppliers are set up to do custom work, and you also need to think carefully about how to protect your ideas if you come up with a new design. Here are some short video tutorials. The ones in bold are highly relevant to your situation.

Video1: Finding suppliers
Video2: Evaluating suppliers
Video3: Negotiations
Video4: Project management and quality control
Video5: Protecting your intellectual property
Video6: Leveraging Global Sources
Video7: How to find and manage partners for logistics services
Video8: Avoiding Scams
Video9: Returning defective merchandise to China
Video10: Resolving a dispute

What will be the minimum order for own design product?

That depends on the supplier you are dealing with and how much they need to adjust their production methods and sub suppliers to meet your design specs

....and how do I send the design to the manufacturer?

I suggest you get your DFM (design for manufacture) files and your IP (Intellectual Property) protected before you send any designs to Asia.

Here is a link to a page which covers DFM in detail: Engaging Engineering Services. I think you will find it very useful to your project.