To find the correct fuse(s), you need to consult your owner's manual. The manual will have a diagram of the fuse box showing the location of each fuse and what circuit it protects. Look for fuses related to the power windows, power seats (sometimes they share a circuit), or possibly even a general accessory circuit. The manual will be your best guide.
If you don't have the owner's manual, you can often find a PDF version online by searching for "[year] [make] [model] owner's manual." Alternatively, you can try searching online for a fuse box diagram specific to your 2003 Dodge Caravan. Just be aware that diagrams may vary slightly depending on options and trim levels.