Ok, time to get creative.
1. Contact the vendor administrator. Tell them that you are not doing well, and that it would help your business if you could contact the previous Breakfast Vendor for some advice and guidance. Naturally, it would be in their interest to see you do well, so they may provide you with previous vendor's(PV) contact details. Once you contact the PV, ask what worked for them. Ask if they knew what worked for the PV before them. If they tell you nothing work for them, or for the previous PV, get out of the business. There could be a whole bunch of PVs before you who couldn't make the Breakfast Slot work.
2. An image of you actually doing business is important, especially if you've only been at it for 2 weeks. There's nothing worse than seeing a vendor all by his lonesome, with no customers. Get your family or friends to come up to your cart
during peak traffic at the station. Pretend to sell them a bagel or something, hand it to them, and they walk off. 5 minutes later, they come back to your cart again, and you sell to them again. Keep repeating it for the 30 - 60 minutes of peak traffic. If the people can see that you are getting customers regularly, that might encourage them to start approaching the cart, and that will encourage more and more people. No one in the station traffic will be hanging around to see the same person/people come up to the cart. Even if they did, that doesn't have any effect.
3. When the Hot Dog cart come at 10, do you have to leave? Or are you able to stay all day, but only serve breakfast food? I have an idea which depends upon the answer. It involes partnership with the hot dog cart. How close are you to the hot dog cart? Maybe someone buying a hotdog also gets a hash brown from you, or a bagel, at a discount.