Legal Question in Business Law in California

You automatically create a sole proprietorship simply by doing business as an individual. It is perfectly legal to puchase things in the US and then take them to other countries for sale (with some limitations for certain technology, weapons, etc.). Only a tiny percentage of exports are subject to any kind of regulatory control at all. It is on the other end where you could run into problems. Every country in the world controls imports and usually taxes them. In every country I know of, bringing in goods to sell without the proper licenses, documents and payment of taxes is considered criminal smuggling. So if you intend to make a business of this, you need to find out what you need to do "back home" to make it legal.