Going to and from the US
 

I posted this on the Canada coronavirus subreddit but here might be a better place. I'm travelling to the US from Ottawa -> Toronto -> Denver, and then exactly the same on the way back. I've been fully vaccinated for 3 weeks now so can skip the quarantine but am unsure of all the different tests I have to take. Here's what I "think" I need, and where I have some questions. If someone has done this before or know someone who has or a blog about it I'd really appreciate it!

1. < 72 hours before my flight from Ottawa -> Toronto what test do I get here? I've heard the "$40" test is ok, but when I went through the Shoppers portal it was $200 (which is fine, just want to make sure I get the right one).
2. Toronto Layover - Anything to do here?
3. Arrive in Denver - Nothing
4. < 72 hours before my flight from Denver -> Toronto, get a test somewhere? What kind? Can I just walk into a walgreens?
5. Toronto Layover - Do I do anything here? Am I given a take home test?
6. Arrive in Ottawa - Can I get another rapid test from shoppers here?

Thanks!

Small point but USA entry covid test is 3 days not 72 hours. And if it is a short trip you can use the same covid test to reenter Canada. And you need to take a covid test upon reentry to Canada. So 3 covid tests in all if you are going for more than a few days. The 4th covid test on day 8 won’t apply to you as you are fully vaccinated.

Small clarification. The US accepts antigen tests (and seems to be the default offering for people flying from Canada to the US). Canada does not accept those, so if you were to rely on the Canadian test on return, make sure it's a molecular test.