Can this keyboard be wireless?
It depends on the keyboard.
For keyboards in the Halcyon Series, including the newest revision Kyria, the answer is: not yet! We've made the controller hot-swappable, but we haven't developed a wireless controller for it yet. Just to be safe, assume that your Halcyon keyboard can't be made wireless.
For keyboards in the Aurora Series, the answer is yes! You'll need to add a pair of nice!nano controllers, and you'll have to source batteries for your keyboard. The Aurora build guide will tell you how to install the nice!nano and the batteries.
For other keyboards, if the keyboard comes preassembled and wireless functionality isn't advertised on the product page, the answer will be no. If the keyboard needs assemly and is compatible with the nice!nano, then it can be made to be wireless.
How do I tell the difference between two split keyboards?
It's mainly down to the layout, which you can learn more about on this page.
Should I learn a new layout?
Not necessarily - but it can be a nice opportunity.