You should wear comfy shoes. (Thank the gods, I already knew this.)
You should sleep well the night before, even if that means going to bed at four and not coming conscious again until noon.
Cons do not start really happening until after 'dane lunch.
Remember to eat.
Do not go for "cool" and bring only your capacious purse and the three-handle-contact tote bag with you. Bring a backpack. They're easier to lug.
Do not go for "cool" and wear a skirt that looks only marginally better than the pants and is also just a touch too tight. Wear the pants instead.
...unless you're cosplaying.
...unless you're cosplaying Faye Valentine, and you're the infamous Man-Faye, in which case please warn the rest of us.
When your roommates don't know jack about cons, it is wise to do some explicit explaining before you head merrily off, so they won't worry if you don't show up until shortly before midnight.
You should also explain that showing up shortly before midnight is in fact showing up early.
Room at con yourself or friend with room at con is preferable to not. Car, also, would be good.
Small cons are good for meeting the guests, but not so great for meeting friends CTY-style.