If your homeschooled child is in 2nd grade, letting them play in the backyard or with their friends in the neighborhood, left to their own imaginations, is probably enough exercise for them to be healthy. As long as you’re minimizing how much TV they watch, and “screen time” in general, there’s very little else that can keep kids sedentary. They’ll be up and moving without another thought because they won’t be able to stop themselves!
If you’re looking for a more formal physical education program, you can sometimes find homeschool gym classes in your community. They usually meet for an hour or two per week, and often involve group sports like soccer or basketball, and games such as kickball, flag football, and tag. Check with your community rec center or YMCA for these homeschool gym classes.
There are plenty of websites that you could use to determine how much physical activity is appropriate for kids this age, and also find suggestions for sports and games as well. The most important thing to remember is that kids want to play and have fun. Call it physical education if you like, but make it fun! Just because they’re homeschooled doesn’t mean they need to miss out on sports!