I have a lot of question because i just started opening my shopify store(I sell fitness products) and some of the apps/marketing that i need to use is requiring me a legal business name. Do i need to open llc account for that? or How do i register a ...

What are the apps that you find very useful for your store? What are they?

Do i need to have or buy barcodes for my products in shopify? If yes please send me to a valid( blog post.