Hi,
When the cart is loaded in memory, HikaShop loads for all the available shipping methods and preselect automatically the first one available.
So if you don't want to get a shipping method preselected before you enter your address, you need to make it so that no shipping method is available before. And it's the same with the taxes.
Before you enter your address, HikaShop temporarily assigns you to the "main tax zone" you set in the HikaShop configuration.
So, say that you have shipping mehtods for the USA and EU only and taxes for the EU only (using the "zone" setting of your shipping methods/taxes). If you set your main tax zone to a country outside the EU and not the USA, then no shipping method nor taxes will be added to your cart until you enter your address.
Note that when you changes the main tax zone, you want to clear the cookies of your browser to reset user session so that the zone can be set in the session again the first time it is needed.