Unknown iPhone passcode set by unknown person?

A passcode has been set on my iPhone without me knowing, now it is locked up. It says here to connect it to my computer and back up then restore my iPhone. Will this clear everything off my phone or will it be the same as it was before it got locked? I have only attempted unlocking it about 5 times in fear of disabling it. I do not want to back up then restore it if it will clear everything off and transfer it to the computer. Are there any alternatives to unlocking my iPhone?

It will clear everything

Contact apple about it.

No as long as you have everything backed up on iCloud or your computer it will be fine. So when you first restore your iPhone, it'll erase everything, but when you start up your phone it'll ask you if you want to set it up as a new device, or restore from (your iPhone name). You would select that, everything should stay the Same, although it may take a few minutes

I phone 5 is disabled it says slide for emergency and it says try in 104 mins