Don't know iphone password

Hi so I bought a AT&T iPhone 5 off the street and when I got home there was a passcode on the iPhone which I don't know. I tried connecting to iTunes on my computer but I couldn't unlock because that iPhone was not originally connected to my computer. How can I unlock this iPhone? I heard that the only way you can unlock it is if you use dfu mode and after doing research I still don't know what a dfu mode really does to a iPhone will it unlock the passcode and let me use the phone? Please help? I tried going back to where i bought it but couldnt the guy who sold it to me because he was some random guy. (Never again) please help?

Iphone 3gs Or Nokia Lumia 620?

Hello i'm a student in school and as far as you know i got a low budget so i was wondering which is the better phone to buy. The iphone 3gs or the nokia lumia 620? If you want to ask me why i want the phone.well i just want it to play games/app and some web browsing on facebook and youtube (i don't want the phone to be laggy though) so please list the better phone in your reply with strong reasons.

LOST IPHONE WHAT TO DO? No insurance?

I have an iphone 4s on a 2 year contract with o2 uk and i've had it for 1 year and almost 3 months now but i have no insurance on it. I lost it on the bus yesterday and already contacted the lost and found service but they claim no one has handed in a black iphone, i have also contacted o2 and all they said was that they could only put a barrier on it and i'd have to buy a new phone, basically they didn't help much.i'm now using the FIND MY IPHONE app that's on there, but my iphone is offline as it was out of battery just before i lost it.
i was wondering if anyone knows a quicker solution to find my iphone! I'd appreciate your help so much! Thank you!

Added (1). On find my iphone it's on offline and the lost mode is pending till it connects to an internet connection so i'm not able to track it down yet.

How to save data on iPhone 4S?

I have a 5 gigabyte plan for my iPhone 4S by AT&T and I use the Internet ALOT. It's already been 10 days and I have used 3 gigabytes worth of data. I DON'T have Wi-Fi in my house or around me either. So how can I save data without going over the 5 gigs? Please put as much as you can.

My Mac OS X 10.7.5 won't find my Wi-Fi but finds my neighbours?

My MacBook Pro Mac OS X 10.7.5 can't find my Wi-Fi but will find my neighbours Wi-Fi? My iPhone and iPad connects to my Wi-Fi no problems! But my MacBook only connects now and again and I don't know why, I have tried going into system preferences and network and adding and removing my Wi-Fi and all other services but nothing works? Any ideas what's going on?

There's no Emoji in my App Store?

I have Emoji Icons on my iPod Touch 5th Gen but on my new iPhone 4 (iOS 6.1.3) it isn't in the app store? I've searched every bit of it and even typed it in and it just isn't there. Can someone help me find it or tell me how to get it maybe from my iPod to my iPhone?

Funny, playful, appropriate & educational Tv shows for 2-4 years olds?

I help take care of toddlers at my church and Me and my friend always try to entertain them. Usually we let them take turns on using our IPhones but all of them want to use the phones at once. So I thought of the idea to let them watch tv shows on YouTube. But I'm not so sure of what some good(shows that will keep them entertained for a good 15 minutes) shows for them to watch.

IPhone has no service randomly and bill is paid

So startling last night at like 1am-now my iphone says searching. I've tried everything… Resetting my phone, reset settings, a hard reset, turning airplane mode on and off. Then I realized my parents phones won't call out either! Theirs will send messages and have bars but everyonce in a while I says no service then goes back to having bars. And when I turn my phone off then turn it back on it'll have a few bars but like two minutes later it goes back to searching. It's so annoying! And I can't call AT&T… No ones phones in the house will mak a call and the BILL HAS BEEN PAID! :/ help!