I look over the event rules and don´t find a dress code

Also, i think it will be good sense wear anything that is not illegal, right?

I read about using comfortable shoes and cothes.

That said, there is any other tips or rules i should attend?

Someone tell me that saturday is the haway shirt day (not that i use something like that)

Any other tip about that part? 
 

• Clean underwear (every day and bring more than one for each day, you never know).
  
• ICC and hotels are open to the public, so there is that.
  
• Probably want to avoid anything that would not be appropriate for your preferred house of worship, or for those that do not worship, avoid anything that would get you kicked off southwest airlines.
  
• Deodorant, it's not optional.   
  
• Avoid perfume, cologne, body spray.  
  
• Con Funk is a real thing, plan to change shirts at least twice a day.  This means into an actual laundered shirt, not one that was frebreezed.
  
• Deodorant, it's not optional.
  
• parts of the ICC are COLD bring something lightweight you can put on in those cases.
  
• Never noticed one day being Hawaiian shirt day.
  
• Deodorant, it's not optional. 
  

Hawaiian Shirt Day is definitely a thing at Gary Con in Wisconsin, and members of that convention have been trying to make it a thing at Gen Con for a few years for the same reasons.  They haven't had as much success, since Gen Con is 30 times the size and the majority of that 30x don't have the same connection to Gary Gygax, either the man or the memory, as the Gary Con crowd does.

Read that a lot.

Specially the deodorant

Got it, tkx for the explanation

I would also just add that although technically not banned (like anything with vulgarity or meant as a threat to anyone - those will get you kicked out), I would also stay away from any political shirts as well, especially if coming from outside the US.

Nowadays the USA has become too political... i.e. stay away from Trump shirts pro and against. Trust me, save yourself a headache.

Find a funny, geeky shirt. This is one place where it is cool. I have a T-shirt that only reads:

I’m Chaotic Neutral. Kinda care, kinda don’t.

G
 

Comfortable shoes made for walking on concrete are the best. Your regular day-to-day shoes may not cut it. Trust me... there is a difference.

If you are cosplaying, unless it is a ridiculously looking over-accentuated Anime style weapon, don't bring it. If you have doubts about it - ask here before you bring it to the Con. 

Socks - you may consider changing your socks halfway through the day. Buy a pack of new ones and throw the old ones away if you don't want to carry around stinky used socks all day.

Deodorant and clean clothes - they're not optional. 

Make sure all the naughty bits are covered. Please... ask a friend for help with this. You may look great in the mirror, but at a distance or from another angle, you may leave more exposed than intended or what convention staff considers decent. (I have seen a lot of people with shirts that are long enough when their arms are down but reach for something, or after a bit of walking, the bottom of their gut hangs out. If you don't mind this, then you are ok. But if it is not intended, then ask a friend if what you are wearing covers everything you intended.) 

Avoid politics, religion and sex. No single finger salutes, etc. Common sense.

Good walking shoes, jeans & a t-shirt are probably the most common, and simplest option.  Shorts are an option, but Daisy Dukes (on either gender) are not a good idea.  As others have said, bring at least one shirt to change into, and avoid anything political.  There are plenty of t-shirt vendors at the con, so you can always pick up a few more gaming-related shirts. 

I use to avoid all days. 

Don´t know you really care, or not right now.

/jk

What about flip flop ?

I keep thinink if i would get my feet hurt

What about flip flop ?I keep thinink if i would get my feet hurt

I usually will advise people think of the convention using "warehouse" rules for footwear.  Nothing open-toed or open-heeled. (though, I doubt anyone will need steel-toes)

Not only are sandals/flip flops not as orthapedically sound as a full comfortable shoe, but in high traffic areas it is very likely someone will step on you at some point.  having someone step on the heel of your flip flop is horrible.

Shorts, tees, comfortable foot wear.  Check
Hat/cap up to you. 
Kilt.  Up to you.  
Backpack.  Up to you.  
Rain Poncho.  Up to you only if you can't get where you want to via the hamster tubes and IF it rains.  

If you have not heard, there is a Gen Con 101 Event on Wednesday.  
 

i cared 2 minutes ago. Now... not so much.

Good way to get through life sometimes too ;)

G

• Loaded with opinions!
  
• Same old stories over & over!
  
• Brand new complaints everyday!
  
• Life-like joints that creak with every move! 
  

If you have not heard, there is a Gen Con 101 Event on Wednesday.