First Step in Checkout page select if User come from Germany or other country

Hi,

There is no mechanism for that. The tax system bases itself on the "current zone" of the user to calculate the taxes rules.
When the user is logged and has at least one address filled, the system will use the address_state and the address_country fields of the address to determine the current zone.
Otherwise, the system will use the "main tax zone" configured in the HikaShop configuration.
Note however that you have the geolocation plugin which, based on the IP address of the user, will automatically set the "current zone" before the user is logged with an address, and thus overrides the setting in the HikaShop configuration. So that might be the better solution here as it doesn't even require the user to do anything, and on top of that, it works directly on the products listings, product details pages, etc.
You can read more about it here:
www.hikashop.com/support/documentation/7...hop-geolocation.html

Now, if you really want to have a selection for the customer to select Germany/other and the taxes base themselves on it, it's not impossible, but it would require the development of a custom plugin for that.