liglig Thank you for providing so much information. Some of those are things I'd considered; a few of them are issues I'll have to dig into. I just ordered a card reader so I can take payments at the con. I'll need to figure out the logistics of taking breaks when I need them. If this takes off I'll look into business cards for the next event.
Since I'm a writer and will primarily be selling my services as a writer, I won't need to prep a lot of merch. I'll probably need to print out some writing samples and place them into binders. I might need to create some more PG-rated examples, too, for sake of filling out that part of my portfolio.
I applied to vend for one day only in the BLFC Bazaar, since I think even one day is going to be a lot for me to handle. Here's to hoping my application is accepted and I get some decent business.