Check your event for how much space you’ll be given. In my experience 10x10 is common and if they provide a table it’s usually one 8ft table and one or two chairs. There’s a couple ways to handle this:
If you have a 8-10 ft table at home awesome use it to practice your setup. If you don’t feel you have enough, and don’t have enough time to get it where you want, using risers or baskets to place items in can help take up space and look fancy. (Also gives you the option to sort by price) If you don’t have a table at home you may want to go get some because many events - especially outdoor ones don’t provide tables at all and you don’t want to be on the floor. People don’t like having to get to the floor to see items and it’ll kill your back. If it’s outdoor you’ll also want a canopy, it protects you from heat or rain and customers are more likely to come to you over one they’ve got to stand in weather for.
If it turns out you don’t have enough space on the table and need a way to display more, instead of leaving the table where it is when you get there (generally at the front of your space so you can hide product safely behind you) push the table to the back of your space. Bring another table or something you can hang items off of. Gridwall is common for the frequent eventers but it can be expensive to invest in so don’t resort to that right away. To make more space arrange tables like this:
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So you need 3 but 2 will do just know the flow of foot traffic so you know which side to place the second table. Bring table cloths and hide any extra items or boxes you used to transport your stuff under the tables.
I’ve seen people arrange their tables so you “walk in” to their booth but this limits traffic, they get trapped in there, some more shy customers won’t come in at all, and when people walking by already see someone in there they don’t want to come in and get cramped or have to navigate around people. They get then"I’ll come back" mentality but if they’ve already spent their money or are tired by the time they come back around you lost them.
Depending on how competitive things are you’ll see people using gimmicks or hooks to attract attention. Don’t get too caught up in that, a hook for people’s attention doesn’t have to be flashy or expensive on you. (Admittedly I have used a gacha machine 
) but something like a large or fancy piece placed high for people to see works too. It’s why I did my Charizard pattern. I wrote it down just in case but I price him at 350$ expecting it to never sell he’s just an eye catcher because he’s about 3ft tall and 4ft wide. Even if you feel you have nothing to show off simply saying “hi” to anyone that walks by helps boost sales because it breaks them out of whatever they’re doing and makes.them look at you, be you’re own attraction! Others use mystery bags but those seem to be waning in popularity as it didn’t take long to figure out most sellers use them to off things that have been hanging out too long.
Don’t worry too much, you’ll be nervous until it starts then it’s all go. Try not to sit too often, and greet everyone that comes by with a smile. Good luck!