I started my business on bridal shows. Yes they are expensive but the saying is true you have to spend money to make money!
First off you ABSOLUTELY need to have samples. If you do nothing else have business cards and samples. That being said you don't have to break your budget by giving away cake samples. People just need a taste they don't need a whole slice or a full sized cupcake. My samples are a one by one inch piece of cake. I make an 11x 15 in cake I cut the squares from that cake and place them in mini cupcake liners I buy from Hobby Lobby. I cut the samples when I am finished setting up that way they don't dry out and you can replenish as needed. Doing it this way gives you about 150 pieces per cake. Much cheaper and perfectly sized for just a taste!
Secondly don't have the normal basic cake flavors make something that the other cake vendors are not going to have. I mean white cake is white cake it has to be really bad white cake to be remembered. No one says o her white cake was better than that booths white cake. Also, have two flavors available one light flavored and one rich or heavy. I usually make my signature strawberry lemonade and peanut butter cup.
Now for extras that make you stand out. Get or make a tablecloth that stands out. Everyone uses white or black. I sewed a multi colored polka dot table cloth from fabric I bought at Hobby Lobby.
Make sure the fake display cakes you make are up to date. Chevron is so in right now. Create a simple cake, a bling cake, and one with some gumpaste flowers or some sort of pattern geometric, chevron, fine dots, etc. People like to see what kind of work you do. So try to make everything as perfect as possible on your display cakes.
Your business name should stand out make sure people know who you are. If you don't have a pamphlet for info then just type up a paper with some flavors, things you make, and prices. Yes prices people want to know what they are getting into. You can state on there somewhere that you work with in any budget. So you can make sure not to scare anyone away if they feel your prices are to high.
Dress professional. Wear a chef coat or have a nice shirt, embroidered with your business name your name and your title. First impressions only happen once! : )
Depending on the size of the event bring a friend or two. You will need help.
I am sorry I wrote so much there is more I can tell you but I didn't want to write a book. lol
Message me or find me of Facebook if you have any questions. My Girls Cake Shop
I hope this helps or relates to you in some way.