Starting a Shipping Company
You could register a Corporation or an LLC (if you are a U.S. resident, you could also register an S-Corporation) to conduct business as a shipping company.
Every state has their own procedures, requirements and fees for each entity type, respectively. Without knowing the state where the business would be conducted, it's difficult to suggest the best entity type for your company. I'd like to invite you to read our research article titled 'Choosing Business Entity'. I believe you will find this information helpful in making the best decision for your specific business needs.