First time product seller and need an advice for scaling a product kit.

Hello Everyone. I started my first product selling in Amazon. Im in the party supply business making party kits. It took me some time to gather and pack all the products in the kits itself(under 500units) in my small apartment. If my product do get popular and a demand volume comes. Is there any possible way or a service out there that exist and I can send my customized boxes and pack all my products in the kit and ship it to me directly or to Amazon. I wouldn’t mine if it was in China(where all my products origin) or here in the US. I would like some advice please.