help give me ideas please!

when I was younger I used to do nothing but WALK. I walked to school, home from school, changed my clothes & all of my friends hung out around town & walked everywhere the whole day & then we'd all walk home. (we lived in a super small town like 5-8 miles long total. now I have 4 kids & walking with all of them is too much of a task itself. I wanted to get a treadmill but idk if I wanna spend the money on that right now. is there any indoor exercises I can do that ate similar to walking without workout equipment? I live in NE OH & all its been doing is raining so even if I wanted to try walking the weather isn't letting me 😂☹ open for any ideas! sidenote: I've already been saving ideas on Pinterest !