Hey guys , im in desperate need of help im starting a side hustle as a FBA selle from india

As a new seller on amazon I will be shipping items directly to US FBA warehouse I need help in regards to

1.Will i have to bear the import charges for sending the item to warehouse

1. What company/brand documents will I need to list my brand

2. Can I still sell my products if my brand/company is not registered or trademarked will I face any challenges during listing or any legal issues later ?