1. You will want to form an entity right away. Since you are not a US citizen, you will not be able to use an S-Corp so your best remaining choices are a C-Corp or LLC (limited liability company). Although without more fact, I can not be sure, it is likely it would be best for you to use an LLC.
2. If you form the LLC in Florida for example (and you should speak to an attorney whether this is best or maybe Delaware), since you will have a warehouse in Vermont, you will need to qualify the entity to do business there.
3. Depending upon what type of business you are starting there may be licensing or permit requirements you should look into.
4. Depending upon the typd of business, evaulating trademarking the name, tag line or logo of your company and products may be very important.
5. Make sure you find yourself a good small business accountant early in the process.
I work with many foreign nationals starting businesses in the U.S. Feel free to reach out if we can be of further assistance.
Disclaimer: This post does not constitute legal advice and does not establish an attorney-client relationship.