Rial is the official currency of Iran but what you most probably will face with, would be Toman. Each Toman is equaled with 10 Rials. So you need to only add a zero to Toman to change it to Rial. When you travel to Iran, you should carry cash with yourself because the ATMs don't work for foreigners. So you can't use your credit card here thanks to the sanctions. But nothing to worry about, because currency exchange shops and banks will do it for you.
Dress code :
Iran is an Islamic country, so you will find a different kind of clothing here. It is not difficult as it is said in the media. For men there is nothing special, just wearing long pants. Shorts are banned for men. Foe women, they must cover their body and hair completely. It means, long pants and full-sleeve shirts and scarves or shawls.
Alcoholic drinks are totally banned in Iran. What you find in Iran is, non-alcoholic beverage malt and soda and yogurt drinks.
I'm afraid to say that the Internet in Iran is not excellent. You may have a little problem sometimes. In big cities it is not a problem, but in small cities you may get bored with the speed. So please be patient!