IPad in different continent

WiFi

WiFi is ubiquitous - standards being global. In context of being able to use your iPad with WiFi networks, you’ll not encounter any country-specific technical difficulties. As such, an iPad purchased in Spain will be usable in any country/region - be it America or Antarctica.

WiFi+Cellular models of iPad are equally usable is most countries. The WiFi capabilities between equivalent WiFi Only and WiFi+Cellular models of iPad are no different.

Cellular

As for Cellular capabilities, models purchased in different regions may have slightly different specifications - in the main tailoring the Cellular chipset to accommodate additional cellular-radio bands used in some countries. That said, most countries now have cellular networks that support modern 4G/LTE cellular radio - and will accommodate the majority of WiFi+Cellular iPad models in most countries. 5G Cellular networks, despite hype, are still in their infancy - most (if not all) supporting 4G/LTE networks.

Warranties

Apple provides an international one-year limited warranty for products purchased in some regions. Warranty service is limited to the available service level in the country where the warranty claim is made. AppleCare+ (an optional purchase) is only valid in the country of purchase.

Generally, you should aim to purchase a device in the country within which you intend to spend most time - as this often simplifies the warranty position should you ever need to call upon it. If travelling for short periods outside of the country of purchase, this may not be a significant concern. More information about applicable Apple warranties can be found here:

https://store.apple.com/Catalog/Images/worldwidewarranty.html

Legal - iOS Warranty Document Us - Apple

yes, works

You may not get warranty service in another country.