Currently, Canada requires you to be fully-vaccinated the full 14-day period for approve vaccines, provide a negative COVID-19 test (PCR test or Abbott ID Now qualifies, Anitgen (rapid) tests do not), and complete the ArriveCAN website or app to check-in before your travel across the border. OH! And make sure your passport hasn't expired. Here are some helpful links about travel into Canada: https://travel.gc.ca/travel-covid https://travel.gc.ca/travel-covid/travel-restrictions/flying-canada-checklist/covid-19-testing-travellers-coming-into-canada
Walgreens and CVS offer online scheduling for the PCR tests with results within 1-2 days. I took a test two weeks ago as an experiment and received my PCR results via text within 27 hours. The text provides a link for you to view your results. Make sure you snag a copy of it as a PDF or screenshot. The 72-hour clock starts when you take the test, NOT when you get the result. They are strict if your 72 hours elapses before you cross that border. The Antigen/Rapid tests do not qualify. It must be a PCR test since it is a molecular test, which is required by Canada to cross the border. For CVS scheduling: https://www.cvs.com/minuteclinic/covid-19-testing I answered YES to the first two questions of the survey about testing, then NO to the remainder to ensure I didn't get charged for the test. For Walgreens scheduling: https://www.walgreens.com/findcare/covid19/testing?ban=covidfy21_newtestingpg_heroban
https://www.canada.ca/en/public-health/services/diseases/coronavirus-disease-covid-19/arrivecan.html
There have been some rumors that you'll get tested again. I've read it inconsistently, but between the Canadian Border Protection and the US Embassy in Canada, from what I understand the testing is random for fully vaccinated individuals. Not everyone who is fully vaccinated will get tested at the border.
You will be asked what your quarantine plan will be if you test positive for COVID. In the very low likelihood that they test you at the border and you receive positive results, I'd suggest just notating on the ArriveCAN app that you'll quarantine in a hotel for 14-days. At that point, if you DO test positive, you would sadly just turn around and leave the country. They cannot keep you there, you can cross back to the US and go home. If you have any questions, call or text me.
There's no requirement to quarantine upon return, nor do you need to get tested, though it's recommended. https://wwwnc.cdc.gov/travel/notices/covid-3/coronavirus-canada