Is my furnace working correctly?

Thanks guys. Will investigate a little. I tried blocking the one vent and didn't notice much difference. There are heat vents everywhere, even the outside kitchen. The underside is all enclose so hopefully it's an easy fix! I would keep it out for until after thanksgiving, but the weekends are already booked with other activities. Wouldn't mind a few more fall trips. Unfortunately I found a good storage deal 3 hours from home so once I put it in, I am not going to retrieve it.