Custom hooks

Hi there, I don’t know if this the proper place to ask the question, I have the Pro version of the plugin and I need to add certain fields like billing_name and billing_address_1 to the template only.

I thought that the plugin let me choose the fields I need but I see that I need to add some hooks, sadly I am newbie with the hooks, actions and filters.

Can you give me a hint how to do it or where to find some examples.

Thanks in advance.