How to get IOS 7 for my iphone 5?

A friend ''jailbroke'' my phone or something like that i don't know how the ''jailbroke'' works and what it does but i heard its a problem if you want ios 7 so how do i get rid of it and keep everything else of my phone and get ios7?

IOS 7 hasn't even been released yet, releases in the Fall.

You have to have a developers account to obtain ios 7 beta.

IOS 7 won't be released to consumers until this Fall. You shouldn't have any trouble upgrading, even though your phone is jailbroken - you'll just lose the jailbreak when you upgrade. This may or may not be a problem for you - you'll lose any jailbreak features you're using, but the new version of iOS incorporates many of the most popular features.