Greetings makakahsa,
After reviewing your post, it sounds like you have two things stopping the iPhone from working correctly. I would recommend that you read these articles, they may be helpful in troubleshooting your issue.
Get help with buttons and switches on your iPhone, iPad, or iPod touch - Apple Support
Once that is sorted you should be able to follow this article.
If your iPhone, iPad, or iPod touch doesn't respond or doesn't turn on - Apple Support
Thanks for using Apple Support Communities.
Take care,
Mario