I have locked my Iphone and now it says "Iphone unavailable". I have downloded the newest version Itunes but I cant restore my phone

What happens when you connect the iPhone to the PC?

If the iPhone is not recognized, see this Apple article: If your computer doesn't recognize your iPhone, iPad, or iPod

https://support.apple.com/en-us/HT204095

Have you forgotten your passcode?, see this Apple article: If you forgot your iPhone passcode

https://support.apple.com/en-us/HT204306

Activation Lock?, see this Apple article: How to remove Activation Lock

https://support.apple.com/en-us/HT201441

See also this Apple article: If your Apple ID is locked or disabled

https://support.apple.com/en-ca/HT204106

I have locked my phone how to unlock