The most important reason you should contact your financial institution before travelling, especially if you're planning on going outside of Canada, is to ensure you will be able to access your account with your ATM card, and that your credit cards will work. ATM cards can be blocked from use outside of the country so your financial institution can unblock them for you for the days you will be travelling. Also, if you financial institution knows about your travel plan, they won't inadvertently disable your card because of suspected fraudulent activity. You should also carry a small amount of cash with you. This way, if your ATM card doesn't work, you can always use your cash.
Most financial institutions will allow you to disable your ATM card or credit card through their mobile app if you misplace or lose them while travelling. Sunrise Credit Union's version is called Lock'n'Block. If you find or recover your card, you can re-activate them through the same feature.
Another way a financial institution can help you before your trip is travel insurance. It's easier to relax knowing you're covered if something goes wrong. There are different insurance packages available that cover everything from lost luggage to health care while in another country. Your Provincial Health Care may not include all medical expenses, so make sure you're protected.
Other things to consider before you leave are:
While not directly related to your financial institution, it's a good idea to visit travel.gc.ca https://travel.gc.ca/, Canada's one-stop-shop for travel information. You can check out travel advice and advisories on your destination, how to get help if there's an emergency when you're travelling, and what you can bring home to Canada.