Generally speaking, the law governing your injuries will be the place where you were injured. For example, if you were driving in Las Vegas and were in a collision, the law of Nevada would apply. You can hire a lawyer in either Nevada or Alberta, but the claim itself will be filed (if not settled by the limitation date) in Nevada and be governed by the laws of Nevada. Some Alberta lawyers are qualified to practice in other jurisdictions (but generally not out of country claims), but you can certainly inquire of a local lawyer to get some guidance.
Another situation with out-of-country injuries might result in you needing an Alberta lawyer is where the insurance coverage of the person that caused your injuries is less than the ‘value’ of your injuries. In those circumstances, you should check and see if you have an SEF 44 endorsement on your own insurance policy. If so, and your insurance is greater than the insurance of the person that caused your injuries, you can sue your own insurer for the excess ‘value’ that your injuries are above the wrongdoer’s insurance. This claim would be brought against your insurer in Alberta, even though your injuries occurred outside of Alberta.