Good luck Dixie!
You may not have been looking for suggestions, but here they come!
Sitting too much does not do us any favors.
I've found that you need to find some kind of exercise you at least "kind of" like to do and then do it at least a few times a week. During my working years as a Manager I got very little exercise at work so I'd hit the gym for the StairMaster and weights after work 3X a week and make a point of getting outdoors for some activity on the weekend.
My go-to since retirement is walking and I concur that hills are critical for strength and endurance.
My usual route is 3 miles with several hundred feet of elevation change and Ive got three different routes in the neighborhood that have different grades depending on how spunky I'm feeling.
My real test for level of fitness is to put on a backpack with 30-35 lbs and go hike a trail that's got at least a thousand feet of elevation gain.
Another favorite is bicycling, I'm lucky in that respect too since I'm about 100 yards from a 30 mile paved rails to trails route with gentle elevation changes since it was a railroad to begin with.
It's a whole different set of muscles involved walking vs. hiking with a backpack vs. Elliptical vs. bicycling. Variety helps IMHO.
Tackling hills is not really feasible in Florida, however- going for an hour of walking and tossing in a few sets of lunges along the way will do you lots of good and build leg/butt strength even if it looks silly.
You can always make it known you are from the "Ministry of silly walks" and developing your abilities.
Rainy days I hit my Elliptical, weights, yoga and core. I'm usually a little sore, but it's a "good" sore
It's good to recognize something needs to change and even better to do something about it.