Tax rate on Purchases

Hello Quickbooks Community, 

I have a quick question. I am new to QuickBooks and new to my own creative business. When classifying my banking transactions, I am having trouble working out what tax options to select. 

For instance, when placing my subscriptions into the subscription category, what tax do I select

0.0 Zero Rated 

20.0 Standard 

Exempt from VAT

No VAT

These are the four options, but for things I am buying for the business, I have no idea which one is correct. 

Thanks for your help!