When my children were small, we didn't have a lot of dollars. An activity we all loved as a family was to grab some sausages ,sauce and a loaf of bread and head to the local park.When we lived near the beach it was even better.Sometimes we bought chips and gravy. We've been lucky, where we've lived there's always been a decent park/playgorund with catering to various ages. We've been to parks big enough they could take their bikes or rollerblades and the little one played on the swings while the bigger ones rode.We have done this in all weathers and the kids would get up on a Sunday and ask could we go for a drive today.
When all 3 of my children wanted to do a sport at once, I chose bowling. It was an affordable team sport, they were in different teams but on the same day and they had a lot of fun.
When I had 3 kids under 4, and it was awful weather for playing, but we wanted to get out of the house, but had no dollars, I would take them to the library. sometimes there would be a story teller, most times not, but they enjoyed choosing their own books and spending time in the kids reading corner.