Hi and welcome to the forum
View media item 647 When you first click on the new Cortana search bar, it will popup a Window asking you if you'd like to setup Cortana--hopefully you said "Yes" to that. If not you can still do it manually. But, Cortana doesn't work on all computers, it's still kinda "glitchy" in my opinion.
It would help if you could answer a couple of basic questions for us, then we can analyze your particular situation, and make some recommendations.
First, what is the EXACT Make/Model of the computer you are trying to run Cortana on? Desktop, Laptop, Tablet?
Next, did you upgraded to W10 from an earlier version of Windows such as Win7/8/8.1/8.1.1? Or did your computer come from the factory with W10 pre-loaded?
Did you install the Nov. 17th W10 upgrade on that Computer yet? If not, you should attempt to do so.
In order for Cortana to function properly, you'll need to have
BOTH a Microphone
AND Speakers on the computer you're trying to use Cortana on. If you have a laptop or tablet, and it's new most of those come with a built-in Mic & tiny Speakers (if you have trouble hearing Cortana, you might need to plug in a cheap pair of external speakers around $15).
If you can't see the OK button, you may have to adjust your screen resolution in Windows Personalize, and zoom down to a lower screen resolution. Seen this problem before in TP. For instance new computers come at 1600x900 resolution from the factory, this can cause a problem with desktop PCs, depending on the Video Card that came with your computer, or if you put in your own aftermarket card. You should dial that back to 1024x768. You may have to go higher or lower depending in your exact hardware.
As far as location goes, I'm not aware of any issues, but you'll have to post that to the Microsoft Forum and look there and see if that's a problem. I'm in the U.S. and haven't been outside the U.S. in 20 years, so I have no idea if Cortana has location issues or not. As far as North America goes.
Once you post back your computer information and how you got your W10, we can make some other recommendations for you and give you some things to try.
Another idea is to go to your local computer store *you guys have Best Buy & Staples in Canada I believe*, and see if they are running Cortana on their demo computers in their stores. If they are having no problems on the store demo computers, it's probably not location related.
Best of luck,
<<<BIGBEARJEDI>>>