Here in the Real World by Sara Pennypacker

11 year old Ware is staying with his grandmother for the summer while his parents are working extra so that they can buy a house, but his grandmother falls and breaks both hips. His summer has now turned into a nightmare of having to go to Rec camp. He HATES Rec camp, but he doesn’t want to cause any trouble for his parents. He overheard them talking about him and how they wish he was normal. As his summer at the Rec starts he finds a dilapidated church next door where a girl, Jolene, is planting papaya plants to sell and make money. Ware decides to turn the church into a medieval castle for himself. Wares summer does not end up like he expects.