Not sure on your fitness level, but assuming you have a little cardio base built up: Flipping tractor tyres end over end can be a really good workout. You could also do that footwork drill for cardio where you hop your feet in amd on different tires. I think searching "crossfit tires" would give some other good ideas.

Also, the rural community I grew up in had a cycling community that would go on bike rides in the morning. Are the roads around where you live safe enough from cars to cycle a bit? Maybe that could be an option. Same for jogging.

As for finding time, really you're just going to have to choose a time and do it. Early morning workouts are the gold standard for people that work full time.

Maybe look I to some body weight exercises? I know the bodyweight fitness subreddit had multiple programs http://old.reddit.com/r/bodyweightfitness/wiki/kb/recommended_routine

I love https://darebee.com/ for all of their free body weight exercises. They have individual workouts and a bunch of programs that you can try. I personally like the programs so it’s less work for me having to pick out my workout everyday, plus some of them have fun rpg storylines.