Helppp, Italian address but only american clients, what about the sales taxes

[barbara5]

I’m opening a shopify store, it's quite finished,  my problem are the taxes, I'm confused about taxes because my address is italian.

My shop is selling t-shirts just for American clients, Printful produces, prints and drop ships my t-shirt.

My address is italian, but I'll sell just for american clients

Have I to choose “All the taxes are included in my final prices”?

Or I have to do something more? Have I to select California because the tshirts are produced in California and they are shipped by there??

I’m totally blocked on this step. 

Thank you a lot for your replies.

barbara