I've done a few rags to riches before where my sims had nothing at all. Like you, I've had them loiter around parks to find left over meals and to use the facilities in gyms. Once they have enough saved up, I'd get them a tent and a cooler, gradually expanding to a little house the more they saved up. I've mostly had my sims start on gardening to earn some money, or go around to find collectibles or go fishing. Last time I did this though I didn't have seasons yet, so it would be interesting to try this again.
