When you return to Town, Junius will explain that the town needs to be rebuilt, and that the Town Hall need building first. Interact with the Town Hall ruins. In exchange for 50 Limestone, 104 Lumber, 48 Copper, and 00000200200, the new Timber style Town Hall will begin construction. After 0000005S5S, interact with the lot again to complete construction. You will be prompted to rename your town from "Ruined Town". The text will default to "Rivercrest", but you can choose any name between 3 and 16 characters. Your new town will Level Up to Town Level 1 and you will receive your rewards.