There are two parts to this question, one is your business of drop shipping which involves sales tax and resale certificates, the other is in regard to filing U.S. tax returns there are several factors involved. If a single-member LLC disregarded, you will have form 5472 and other forms depending on the ownership of your LLC, and treaties. The big part is if you are considered to have effectively connected income or not. The subject is advanced and a consult with a tax attorney or CPA who works with tax treaties and protective returns in the U.S. is recommended. This is a service recommended to open a US bank account without travel. Learn more at https://www.nvinc.com/service/us-bank-account-service/
I hope this helps.