I'm looking for effective workout plans that don't require any equipment

I teach at a K-8 school and sometimes join the older kids in sports, but I’ve noticed I get tired much quicker than I used to, and then I feel sore for days afterward. I’m on the bigger side and have been trying to cut calories. With a 1-year-old, my days start at 5am and go until 8pm, leaving me with very little free time. I also don’t have extra money to spend, so I need to find ways to work out with what I have.