Help with bulk contract and quality inspection

I have a factory in Guangzhou that I want to work with. I had prototypes done with them of my custom design and want to place a bulk order of 200pcs.

What are usually the next steps and what should I look out for?

I need help with making a proper contract that would protect me and my design - are there some companies/ websites where I can find a good one?

I also need an agent that can help me with quality check once the bulk order is done.

Any tips?