I’ve been to 9 provinces and 2 territories in Canada.
12 states and DC in the US.
(I’m defining “been to” as actually spent more than 24 hours on the ground. Fly/overs and short landings don’t count .)
In Canada, I’m missing the smallest and the largest: Prince Edward Island and Nunavut.
My US states are California, Connecticut, Florida, Hawaii, Massachusetts, Nevada, New York, North Dakota, South Dakota , Vermont and Washington.
Canada, only Ontario (and was an infant in arms at the time, so while over 24 hours, is still a technicality).
For the US, 15 states.
California, Arizona, New Mexico, Colorado, Nevada, Nebraska, Kansas, Texas, New York, Pennsylvania, Florida, North Carolina, South Carolina, Massachusetts, Minnesota
Of those, New Mexico, Colorado, Kansas, Texas, Pennsylvania, North and South Carolina, Massachusetts and Minnesota were all over a month at a time (sometimes more than once).
Similarly only counting spending a day or more on the ground there, I’m at 40 U.S. states.
I’ve only been to Canada once, and that, only to Ontario.
Well,then, you’ve been to the Centre of the Universe.
In their eyes, at least.
Ha! 
But, truly, I’d love to see more of Canada; I should do so while time is still on my side.
It does become a matter of what counts as a visit. I’ve been through Yellowstone on a motorcycle, but I don’t think it was more than 24 hours in the state.
By my own definition, I’ve been to 25 states and 4 provinces.
Lessee… California, Oregon, Washington, Alaska, Hawaii, Nevada, Arizona, Utah, Idaho, Montana, Colorado, Texas, Illinois, Virginia, and D.C.
Canada: B.C., twice. But…
The first time I was 5 years old. We were visiting friends in Seattle, and went up to Vancouver for a few hours.
The second time was a couple of months ago. My wife and I took a cruise from Alaska to Vancouver. The only time we got off the ship in Canada was the final disembarkation. We then spent several hours on a tour bus checking out the city, before heading to the airport.
According to the OP, these visits don’t count. But I don’t see why my recent visit shouldn’t.
Ontario.
Alabama, Arizona, California, Connecticut, D.C., Florida, Georgia, Ilinois, Indiana, Kansas, Kentucky, Louisiana, Michigan, Missouri, Nebraska, Nevada, New Jersey, New Mexico, Ohio, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, Wisconsin.
Canada: BC, Alberta, Ontario, Quebec
US: 39 states (incl. DC) (lived or worked in nine for at least six months; six I’ve never even driven through or landed in)
I’m a homebody. I’ve been to California once for ~3 days, Wyoming twice for 3 or 4 days each, and been to Washington, Idaho, and Montana perhaps 20 times each. On one trip to Montana I stepped perhaps 50 feet over the border into Canada and stayed for all of 5 minutes. Don’t think that counts.
The rest of my life I’ve spent in Oregon.
For me, ten Canadian provinces. What’s even better, is that if you add up all the drives I’ve made from place to place in Canada, I’ve driven from St. John’s, Newfoundland; to Victoria, BC.
One territory counted by a three-day visit to Yellowknife: the Northwest Territories.
As for US states, it’s 18: California, Washington, Montana, Nevada, Texas, Florida, Colorado, Nebraska, Iowa, Illinois, Indiana, Michigan, New York, Pennsylvania, New Jersey, Vermont, New Hampshire, and Maine. Plus Washington DC, which isn’t a state, but I’ve certainly been there.
4 Canadian provinces:
Ontario
Quebec
New Brunswick
Prince Edward Island
24 US States, not counting Washington DC which I’ve also visited:
Hawaii, California, Texas
New York, New Jersey, Connecticut
Massachusetts, New Hampshire, Vermont
Maine, Rhode Island, Delaware
Maryland, Virginia, Ohio
Pennsylvania, Michigan, Illinois
Kentucky, North Carolina, Georgia
South Carolina, Florida, Washington State
All of these are 24+ hours on the ground. I’ve spent around 8 hours in Alaska, the Anchorage airport, and maybe 6 in Colorado, the airport in Denver.
I’ve been to all 50 states and DC. Hawaii was my first, and Alaska was my 50th.
In Canada I’ve been to 6 provinces: British Columbia, Ontario, Quebec, New Brunswick, Nova Scotia, and Prince Edward Island.
I have not yet been to the Yukon Territory, the Northwest Territories, Nunavut, Alberta, Saskatchewan, Manitoba, and Newfoundland and Labrador.
I lived my first 13 years in Upstate NY without leaving the state once, finally driving with my parents through PA and MD to DC to see my grandparents. I added MN and Ontario a bit later until finally moving abroad after grad school.
I have since visited probably 50 countries.
My forays across the Atlantic have been much more limited:
Ontario, Quebec, BC
New York, Illinois, Massachusetts, Florida, California
But:
14 other European countries
Turkey
Kenya
Japan, S Korea, Taiwan, Singapore, Malaysia, Pakistan
Australia
(TBH, cities in all of those, so basically just scratching the surface)
I have been to all 50 states and DC and Puerto Rico. Completed our 50 states goal when we landed in Honolulu on November 20, 2008. I have been to every state capitol except Alaskas. I have been to the state fair in 23 states.
If I got 51% of the vote in every county/parish I have been to, and 0% in every county/parish I have not been to I would win an electoral and popular vote election as POTUS.
Have only been to 2 Canadian Provinces: Ontario and Quebec.
Well, I keep track of places I’ve spent any time actually doing anything in besides transiting through. Daytrip to Vermont to hike counts, driving through South Dakota doesn’t even if I spent a night in a motel there. Spending a whole work day in a conference in Tennessee counts even if I flew in early morning and out late in the afternoon.
44 states and 7 Canadian provinces.
Never been to:
Alaska, South Dakota, North Dakota, New Mexico, Idaho, Wyoming, Saskatchewan, Manitoba, N&L.
Non-State political entities of the US I have been to: DC, Puerto Rico & USVI.
I have not been to American Samoa, US Mariana Islands, Guam, Northwest Territories, Yukon or Nunavut.
Provinces: (9 + 1 airport, both territories) All. If you include BC by being in the Vancouver airport (I was actually there for more than 24 hours due to numerous flight delays). Otherwise, all but BC.
States: (12 + 1 airport) Indiana, Colorado, New York, Maine, Vermont, California, Michigan, Kentucky, Tennessee, Missouri, Ohio, Pennsylvania, Illinois (Chicago airport).
Other countries: Spain, Japan, Romania, France (twice), Belgium, Croatia, Greece.
I’ll use this definition since it’s easier than trying to add hours together.
Canada:
U.S.:
I’ve spent material numbers of days in both Montreal & Vancouver, so that scores me Quebec & British Columbia. I’ve overnighted in Toronto, but not 24 hours worth. That’s it for our fine Northern friends.
I’ve resided long-term (>1 year) in 6 US states (CA, AZ, OK, NV, MO, FL) and been temporarily stationed (> 1 month) in 4 more (WA, NM, NY, TX). I’ve vacationed or worked multiple consecutive days in 21 more states (IL, SC, WI, OR, UT, CO, KS, NJ, GA, TN, MA, AK, HI, CT, LA, MN, MI (lower), KY, MD, ME, & OH) that I can recall. Plus the district of DC & the territory of PR.
I’ve stayed >24 consecutive hours in probably ~8 more, but no practical way to recall or research which. There gets to be a lot of overlap wherein I’ve had long layovers in states where I’ve also vacationed or lived.
So definitely 31 US states, definitely two US non-state entities, and probably over 40 total.
Which is a decent haul for having made no particular attempt to check all the boxes and for having spent a couple decades not vacationing at all.