I would totally go, if it wasn't so far away && I had enough money...OTL;;

Well, being a frequent con go-er ((I'm at 3-4 a year && a few small gatherings in between)), I can tell you what I know. It's a lot but here's some of the basics. ;D

1) Food...
-Is hella expensive at the con centers usually ((At ours, $8 for a terrible burger D8)). I'd look around the area to get some cheap food that you might actually like ((Most con centers have a lot of resteraunts nearby)) :]
-If that's not an option, go grocery shopping before && bring non-perishable food with you ((you'll be glad you did later ))
-DON'T FORGET TO EAT! Stupid advice, I know...but you have no idea how easy it is to get distracted && not eat...by the end of the con, you'll know if you didn't eat enough xD

2) Money/Dealers Hall
-Bring tons of extra money. As Anji said, you'll find some great stuff in the dealer's hall. This bring me to the next point...
-If it's not something you know is gonna sell fast, wait to buy it until the last day. Prices go way down the last day && you'll get some better deals :]
-People in the dealers hall can be rude ((bump into you without saying sorry; etc)). Make sure if you're going in the hall, that your cosplay isn't something that can bump into && destroy ((because yours is being made for you, I don't think you have to worry too much about this))

3) People
-As mentioned before, you will get glomped randomly...so prepare for fangirls && the occasional fanboy jumping on you at random times of the day.
-Just because other people do it, try not to glomp without permission. You could destroy a costume someone worked really hard on && that's the saddest thing to see DDD:
-Also, depending on how people like your cosplay; either no one will reconize you or you'll be swamped for pictures all day. Prepare for either scenario.
-Some people...can be mean :l Just shake those people off, they're notorious for ruining people's cons, so don't let it get to you

4) Masquerade
-Also if you're thinking of doing Masquerade ((costume contest)), make sure it's not judged on Craftsmanship only ((the costume)). In those kind of contests, you have to make your entire costume && have pictures, explain the process; etc. So if you're thinking of doing the contest, ask them first if it's okay to compete in that contest && say to not judge on Craftsmanship.

Most importantly....enjoy the con && tell us how it goes!