Completely unnecessary. This is a networking event, not a formal job interview. If it makes you feel more comfortable, sure, I guess you can…but remember, it’s in a bar, and you’re there to have conversations and make connections. I wouldn’t suggest showing up in destroyed jeans and a tattered t-shirt either.
The best way to get you in the right mindset is this: Think of being at a bar (because, well, our events take place in bars…), and imagine that at the table next to you, you hear someone talking about needing to hire someone for what is basically your dream job.
Don’t wear anything that would keep you from approaching that person and starting a conversation.